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curl(1)                        Curl Manual                        curl(1)

NAME
       curl - transfer a URL

SYNOPSIS
       curl [options / URLs]

DESCRIPTION
       curl  is a tool to transfer data from or to a server, using one of
       the supported protocols (DICT,  FILE,  FTP,  FTPS,  GOPHER,  HTTP,
       HTTPS,  IMAP,  IMAPS,  LDAP,  LDAPS, POP3, POP3S, RTMP, RTSP, SCP,
       SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and  TFTP).  The  command  is
       designed to work without user interaction.

       curl  offers  a  busload of useful tricks like proxy support, user
       authentication, FTP upload, HTTP post, SSL  connections,  cookies,
       file  transfer  resume, Metalink, and more. As you will see below,
       the number of features will make your head spin!

       curl is powered by libcurl for all transfer-related features.  See
       libcurl(3) for details.

URL
       The  URL  syntax  is  protocol-dependent.  You'll  find a detailed
       description in RFC 3986.

       You can specify multiple URLs or parts of  URLs  by  writing  part
       sets within braces as in:

         http://site.{one,two,three}.com

       or you can get sequences of alphanumeric series by using [] as in:

         ftp://ftp.example.com/file[1-100].txt

         ftp://ftp.example.com/file[001-100].txt    (with leading zeros)

         ftp://ftp.example.com/file[a-z].txt

       Nested  sequences  are not supported, but you can use several ones
       next to each other:

         http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html

       You can specify any amount of URLs on the command line. They  will
       be  fetched in a sequential manner in the specified order. You can
       specify command line options and URLs mixed and in  any  order  on
       the command line.

       You  can  specify  a  step counter for the ranges to get every Nth
       number or letter:

         http://example.com/file[1-100:10].txt

         http://example.com/file[a-z:2].txt

       When using [] or {} sequences when invoked  from  a  command  line
       prompt, you probably have to put the full URL within double quotes
       to avoid the shell from interfering with it. This  also  goes  for
       other  characters  treated  special, like for example '&', '?' and
       '*'.

       Provide the IPv6 zone index in the URL with an escaped  percentage
       sign and the interface name. Like in

         http://[fe80::3%25eth0]/

       If  you  specify URL without protocol:// prefix, curl will attempt
       to guess what protocol you might want. It  will  then  default  to
       HTTP  but  try  other protocols based on often-used host name pre‐
       fixes. For example, for host names starting with "ftp." curl  will
       assume you want to speak FTP.

       curl  will  do its best to use what you pass to it as a URL. It is
       not trying to validate it as a syntactically correct  URL  by  any
       means but is instead very liberal with what it accepts.

       curl  will  attempt to re-use connections for multiple file trans‐
       fers, so that getting many files from the same server will not  do
       multiple  connects  /  handshakes.  This improves speed. Of course
       this is only done on files specified on a single command line  and
       cannot be used between separate curl invokes.

PROGRESS METER
       curl  normally  displays a progress meter during operations, indi‐
       cating the amount of transferred data, transfer speeds  and  esti‐
       mated  time left, etc. The progress meter displays number of bytes
       and the speeds are in bytes per second. The suffixes (k, M, G,  T,
       P)  are  1024  based.  For example 1k is 1024 bytes. 1M is 1048576
       bytes.

       curl displays this data to the terminal  by  default,  so  if  you
       invoke  curl  to  do an operation and it is about to write data to
       the terminal, it disables the progress meter as otherwise it would
       mess up the output mixing progress meter and response data.

       If  you  want  a progress meter for HTTP POST or PUT requests, you
       need to redirect the response output to a file, using shell  redi‐
       rect (>), -o, --output or similar.

       It  is not the same case for FTP upload as that operation does not
       spit out any response data to the terminal.

       If you prefer a progress "bar" instead of the regular  meter,  -#,
       --progress-bar  is  your friend. You can also disable the progress
       meter completely with the -s, --silent option.

OPTIONS
       Options start with one or two dashes. Many of the options  require
       an additional value next to them.

       The  short  "single-dash" form of the options, -d for example, may
       be used with or without a space between it and its value, although
       a  space  is a recommended separator. The long "double-dash" form,
       -d, --data for example, requires a space between it and its value.

       Short version options that don't need any additional values can be
       used  immediately  next  to  each  other, like for example you can
       specify all the options -O, -L and -v at once as -OLv.

       In general, all boolean options are enabled with --option and  yet
       again  disabled  with --no-option. That is, you use the exact same
       option name but prefix it with "no-". However,  in  this  list  we
       mostly only list and show the --option version of them. (This con‐
       cept with --no  options  was  added  in  7.19.0.  Previously  most
       options  were  toggled  on/off on repeated use of the same command
       line option.)

       --abstract-unix-socket <path>
              (HTTP) Connect through  an  abstract  Unix  domain  socket,
              instead of using the network.  Note: netstat shows the path
              of an abstract socket prefixed with '@', however the <path>
              argument should not have this leading character.

              Added in 7.53.0.

       --alt-svc <file name>
              (HTTPS) WARNING: this option is experimental. Do not use in
              production.

              This option enables the alt-svc parser in curl. If the file
              name points to an existing alt-svc cache file, that will be
              used. After a completed transfer, the cache will  be  saved
              to the file name again if it has been modified.

              Specify  a "" file name (zero length) to avoid loading/sav‐
              ing and make curl just handle the cache in memory.

              If this option is used several times, curl will  load  con‐
              tents  from all the files but the last one will be used for
              saving.

              Added in 7.64.1.

       --anyauth
              (HTTP) Tells curl to figure out  authentication  method  by
              itself,  and use the most secure one the remote site claims
              to support. This is done  by  first  doing  a  request  and
              checking  the  response-headers,  thus possibly inducing an
              extra network round-trip. This is used instead of setting a
              specific  authentication  method,  which  you  can  do with
              --basic, --digest, --ntlm, and --negotiate.

              Using --anyauth is not recommended if you do  uploads  from
              stdin,  since it may require data to be sent twice and then
              the client must be able to rewind. If the need should arise
              when uploading from stdin, the upload operation will fail.

              Used together with -u, --user.

              See also --proxy-anyauth and --basic and --digest.

       -a, --append
              (FTP  SFTP)  When used in an upload, this makes curl append
              to the target file instead of overwriting it. If the remote
              file  doesn't  exist,  it  will be created.  Note that this
              flag is ignored by some SFTP servers (including OpenSSH).

       --basic
              (HTTP) Tells curl to use HTTP Basic authentication with the
              remote host. This is the default and this option is usually
              pointless, unless you use it to override a  previously  set
              option that sets a different authentication method (such as
              --ntlm, --digest, or --negotiate).

              Used together with -u, --user.

              See also --proxy-basic.

       --cacert <file>
              (TLS) Tells curl to use the specified certificate  file  to
              verify  the peer. The file may contain multiple CA certifi‐
              cates. The certificate(s) must be in PEM  format.  Normally
              curl  is  built  to  use  a  default file for this, so this
              option is typically used to alter that default file.

              curl   recognizes   the    environment    variable    named
              'CURL_CA_BUNDLE' if it is set, and uses the given path as a
              path to a CA cert bundle. This option overrides that  vari‐
              able.

              The  windows  version of curl will automatically look for a
              CA certs file named  ´curl-ca-bundle.crt´,  either  in  the
              same  directory  as  curl.exe,  or  in  the Current Working
              Directory, or in any folder along your PATH.

              If curl is built against the NSS SSL library, the  NSS  PEM
              PKCS#11  module  (libnsspem.so)  needs  to be available for
              this option to work properly.

              (iOS and macOS only) If curl is built against Secure Trans‐
              port,  then  this option is supported for backward compati‐
              bility with other SSL engines, but it should not be set. If
              the  option is not set, then curl will use the certificates
              in the system and user Keychain to verify the  peer,  which
              is the preferred method of verifying the peer's certificate
              chain.

              (Schannel only) This option is supported  for  Schannel  in
              Windows  7 or later with libcurl 7.60 or later. This option
              is supported for  backward  compatibility  with  other  SSL
              engines; instead it is recommended to use Windows' store of
              root certificates (the default for Schannel).

              If this option is used several times, the last one will  be
              used.

       --capath <dir>
              (TLS) Tells curl to use the specified certificate directory
              to verify the peer. Multiple paths can be provided by sepa‐
              rating  them with ":" (e.g.  "path1:path2:path3"). The cer‐
              tificates must be in PEM  format,  and  if  curl  is  built
              against  OpenSSL,  the  directory  must have been processed
              using the c_rehash utility  supplied  with  OpenSSL.  Using
              --capath can allow OpenSSL-powered curl to make SSL-connec‐
              tions much more efficiently  than  using  --cacert  if  the
              --cacert file contains many CA certificates.

              If  this  option  is  set, the default capath value will be
              ignored, and if it is used several times, the last one will
              be used.

       --cert-status
              (TLS)  Tells  curl  to verify the status of the server cer‐
              tificate by using the Certificate Status Request (aka. OCSP
              stapling) TLS extension.

              If  this  option is enabled and the server sends an invalid
              (e.g. expired) response, if the response suggests that  the
              server  certificate has been revoked, or no response at all
              is received, the verification fails.

              This is currently only implemented in the  OpenSSL,  GnuTLS
              and NSS backends.

              Added in 7.41.0.

       --cert-type <type>
              (TLS)  Tells curl what type the provided client certificate
              is using. PEM, DER, ENG and P12 are recognized  types.   If
              not specified, PEM is assumed.

              If  this option is used several times, the last one will be
              used.

              See also -E, --cert and --key and --key-type.

       -E, --cert <certificate[:password]>
              (TLS) Tells curl to use the  specified  client  certificate
              file  when  getting a file with HTTPS, FTPS or another SSL-
              based protocol. The certificate must be in  PKCS#12  format
              if using Secure Transport, or PEM format if using any other
              engine.  If the optional password isn't specified, it  will
              be  queried  for  on  the  terminal.  Note that this option
              assumes a "certificate" file that is the  private  key  and
              the  client  certificate  concatenated!  See -E, --cert and
              --key to specify them independently.

              If curl is built against the  NSS  SSL  library  then  this
              option can tell curl the nickname of the certificate to use
              within the NSS database defined by the environment variable
              SSL_DIR  (or  by  default  /etc/pki/nssdb).  If the NSS PEM
              PKCS#11 module (libnsspem.so) is available then  PEM  files
              may  be  loaded. If you want to use a file from the current
              directory, please precede it with "./" prefix, in order  to
              avoid  confusion with a nickname.  If the nickname contains
              ":", it needs to be preceded by "\" so that it is not  rec‐
              ognized  as  password  delimiter.  If the nickname contains
              "\", it needs to be escaped as "\\" so that it is not  rec‐
              ognized as an escape character.

              If  curl  is  built against OpenSSL library, and the engine
              pkcs11 is available, then a PKCS#11 URI (RFC 7512)  can  be
              used  to specify a certificate located in a PKCS#11 device.
              A string beginning with "pkcs11:" will be interpreted as  a
              PKCS#11  URI.  If  a  PKCS#11  URI  is  provided,  then the
              --engine option will be set as "pkcs11" if  none  was  pro‐
              vided  and  the  --cert-type option will be set as "ENG" if
              none was provided.

              (iOS and macOS only) If curl is built against Secure Trans‐
              port, then the certificate string can either be the name of
              a certificate/private key in the system or  user  keychain,
              or  the  path  to a PKCS#12-encoded certificate and private
              key. If you want to use a file from the current  directory,
              please  precede it with "./" prefix, in order to avoid con‐
              fusion with a nickname.

              (Schannel only) Client certificates must be specified by  a
              path expression to a certificate store. (Loading PFX is not
              supported; you can import it to a store first). You can use
              "<store  location>\<store name>\<thumbprint>" to refer to a
              certificate in the system certificates store, for  example,
              "CurrentUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a".
              Thumbprint is usually a SHA-1 hex string which you can  see
              in  certificate details. Following store locations are sup‐
              ported:  CurrentUser,  LocalMachine,  CurrentService,  Ser‐
              vices,   CurrentUserGroupPolicy,   LocalMachineGroupPolicy,
              LocalMachineEnterprise.

              If this option is used several times, the last one will  be
              used.

              See also --cert-type and --key and --key-type.

       --ciphers <list of ciphers>
              (TLS) Specifies which ciphers to use in the connection. The
              list of ciphers must specify valid ciphers. Read up on  SSL
              cipher list details on this URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              If  this option is used several times, the last one will be
              used.

       --compressed-ssh
              (SCP SFTP) Enables built-in SSH  compression.   This  is  a
              request, not an order; the server may or may not do it.

              Added in 7.56.0.

       --compressed
              (HTTP) Request a compressed response using one of the algo‐
              rithms curl supports, and save the  uncompressed  document.
              If  this option is used and the server sends an unsupported
              encoding, curl will report an error.

       -K, --config <file>

              Specify a text file to read curl arguments from.  The  com‐
              mand  line arguments found in the text file will be used as
              if they were provided on the command line.

              Options and their parameters must be specified on the  same
              line  in  the  file, separated by whitespace, colon, or the
              equals sign. Long option names can optionally be  given  in
              the  config  file  without the initial double dashes and if
              so, the colon or equals characters can be used  as  separa‐
              tors.  If  the  option is specified with one or two dashes,
              there can be no  colon  or  equals  character  between  the
              option and its parameter.

              If  the  parameter contains whitespace (or starts with : or
              =), the parameter must be enclosed  within  quotes.  Within
              double  quotes,  the  following escape sequences are avail‐
              able: \\, \", \t, \n, \r and \v. A backslash preceding  any
              other  letter  is  ignored. If the first column of a config
              line is a '#' character, the  rest  of  the  line  will  be
              treated  as  a  comment. Only write one option per physical
              line in the config file.

              Specify the filename to -K, --config as '-'  to  make  curl
              read the file from stdin.

              Note  that  to be able to specify a URL in the config file,
              you need to specify it using the --url option, and  not  by
              simply  writing  the URL on its own line. So, it could look
              similar to this:

              url = "https://curl.haxx.se/docs/"

              When curl is invoked, it (unless  -q,  --disable  is  used)
              checks  for a default config file and uses it if found. The
              default config file is checked for in the following  places
              in this order:

              1)  curl  tries to find the "home dir": It first checks for
              the CURL_HOME and  then  the  HOME  environment  variables.
              Failing  that,  it  uses  getpwuid()  on  Unix-like systems
              (which returns the home dir given the current user in  your
              system).  On  Windows, it then checks for the APPDATA vari‐
              able, or as a last  resort  the  '%USERPROFILE%\Application
              Data'.

              2) On windows, if there is no .curlrc file in the home dir,
              it checks for one in the same dir the  curl  executable  is
              placed.  On  Unix-like  systems, it will simply try to load
              .curlrc from the determined home dir.

              # --- Example file ---
              # this is a comment
              url = "example.com"
              output = "curlhere.html"
              user-agent = "superagent/1.0"

              # and fetch another URL too
              url = "example.com/docs/manpage.html"
              -O
              referer = "http://nowhereatall.example.com/"
              # --- End of example file ---

              This option can be used multiple  times  to  load  multiple
              config files.

       --connect-timeout <seconds>
              Maximum time in seconds that you allow curl's connection to
              take.  This only limits the connection phase,  so  if  curl
              connects  within the given period it will continue - if not
              it will exit.  Since version 7.32.0,  this  option  accepts
              decimal values.

              If  this option is used several times, the last one will be
              used.

              See also -m, --max-time.

       --connect-to <HOST1:PORT1:HOST2:PORT2>

              For a request to the given  HOST1:PORT1  pair,  connect  to
              HOST2:PORT2  instead.   This  option  is suitable to direct
              requests at a specific server, e.g. at a  specific  cluster
              node  in  a cluster of servers. This option is only used to
              establish the network connection. It does  NOT  affect  the
              hostname/port  that is used for TLS/SSL (e.g. SNI, certifi‐
              cate  verification)  or  for  the  application   protocols.
              "HOST1"  and  "PORT1" may be the empty string, meaning "any
              host/port". "HOST2" and  "PORT2"  may  also  be  the  empty
              string, meaning "use the request's original host/port".

              A  "host" specified to this option is compared as a string,
              so it needs to match the name used in request URL.  It  can
              be  either  numerical  such as "127.0.0.1" or the full host
              name such as "example.org".

              This option can be used many  times  to  add  many  connect
              rules.

              See also --resolve and -H, --header. Added in 7.49.0.

       -C, --continue-at <offset>
              Continue/Resume  a previous file transfer at the given off‐
              set. The given offset is the exact  number  of  bytes  that
              will  be skipped, counting from the beginning of the source
              file before it is transferred to the destination.  If  used
              with  uploads, the FTP server command SIZE will not be used
              by curl.

              Use "-C -" to tell curl to automatically find out where/how
              to resume the transfer. It then uses the given output/input
              files to figure that out.

              If this option is used several times, the last one will  be
              used.

              See also -r, --range.

       -c, --cookie-jar <filename>
              (HTTP)  Specify  to  which  file you want curl to write all
              cookies after a completed operation. Curl writes all  cook‐
              ies  from its in-memory cookie storage to the given file at
              the end of operations. If no cookies  are  known,  no  data
              will  be  written.  The file will be written using the Net‐
              scape cookie file format. If you set the  file  name  to  a
              single dash, "-", the cookies will be written to stdout.

              This  command  line  option will activate the cookie engine
              that makes curl record and  use  cookies.  Another  way  to
              activate it is to use the -b, --cookie option.

              If the cookie jar can't be created or written to, the whole
              curl operation won't fail or even report an error  clearly.
              Using  -v, --verbose will get a warning displayed, but that
              is the only visible feedback you get  about  this  possibly
              lethal situation.

              If  this  option  is used several times, the last specified
              file name will be used.

       -b, --cookie <data|filename>
              (HTTP) Pass the data to  the  HTTP  server  in  the  Cookie
              header.  It is supposedly the data previously received from
              the server in a "Set-Cookie:" line.  The data should be  in
              the format "NAME1=VALUE1; NAME2=VALUE2".

              If  no  '='  symbol  is used in the argument, it is instead
              treated as a filename  to  read  previously  stored  cookie
              from.  This  option  also activates the cookie engine which
              will make curl record incoming cookies, which may be  handy
              if you're using this in combination with the -L, --location
              option or do multiple URL transfers on the same invoke.  If
              the  file  name is exactly a minus ("-"), curl will instead
              the contents from stdin.

              The file format of the file to read cookies from should  be
              plain   HTTP   headers   (Set-Cookie  style)  or  the  Net‐
              scape/Mozilla cookie file format.

              The file specified with -b, --cookie is only used as input.
              No  cookies  will be written to the file. To store cookies,
              use the -c, --cookie-jar option.

              Exercise caution if you are using this option and  multiple
              transfers  may occur.  If you use the NAME1=VALUE1; format,
              or in a file use the Set-Cookie format and don't specify  a
              domain,  then the cookie is sent for any domain (even after
              redirects are followed) and cannot be modified by a server-
              set  cookie.  If  the cookie engine is enabled and a server
              sets a cookie of the same name then both will be sent on  a
              future  transfer  to  that  server,  likely  not  what  you
              intended.  To address these issues set  a  domain  in  Set-
              Cookie  (doing  that  will  include sub domains) or use the
              Netscape format.

              If this option is used several times, the last one will  be
              used.

              Users  very often want to both read cookies from a file and
              write updated cookies back to a file,  so  using  both  -b,
              --cookie  and  -c, --cookie-jar in the same command line is
              common.

       --create-dirs
              When used in conjunction with the -o, --output option, curl
              will  create  the  necessary  local  directory hierarchy as
              needed. This option creates the dirs mentioned with the -o,
              --output  option,  nothing  else. If the --output file name
              uses no dir or if the dirs it mentions  already  exist,  no
              dir will be created.

              Created  dirs  are  made  with mode 0750 on unix style file
              systems.

              To create remote directories when using FTP  or  SFTP,  try
              --ftp-create-dirs.

       --crlf (FTP  SMTP)  Convert  LF  to CRLF in upload. Useful for MVS
              (OS/390).

              (SMTP added in 7.40.0)

       --crlfile <file>
              (TLS) Provide a file using PEM format  with  a  Certificate
              Revocation List that may specify peer certificates that are
              to be considered revoked.

              If this option is used several times, the last one will  be
              used.

              Added in 7.19.7.

       --data-ascii <data>
              (HTTP) This is just an alias for -d, --data.

       --data-binary <data>
              (HTTP)  This  posts data exactly as specified with no extra
              processing whatsoever.

              If you start the data with the letter @, the rest should be
              a  filename.   Data  is  posted  in a similar manner as -d,
              --data does, except that newlines and carriage returns  are
              preserved and conversions are never done.

              Like -d, --data the default content-type sent to the server
              is application/x-www-form-urlencoded. If you want the  data
              to  be  treated as arbitrary binary data by the server then
              set the content-type  to  octet-stream:  -H  "Content-Type:
              application/octet-stream".

              If  this  option  is used several times, the ones following
              the first will append data as described in -d, --data.

       --data-raw <data>
              (HTTP) This posts data similarly to -d, --data but  without
              the special interpretation of the @ character.

              See also -d, --data. Added in 7.43.0.

       --data-urlencode <data>
              (HTTP)  This  posts  data,  similar to the other -d, --data
              options with the exception that this performs URL-encoding.

              To be CGI-compliant, the <data> part should  begin  with  a
              name  followed  by a separator and a content specification.
              The <data> part can be passed to curl using one of the fol‐
              lowing syntaxes:

              content
                     This  will make curl URL-encode the content and pass
                     that on. Just be careful so that the content doesn't
                     contain  any  = or @ symbols, as that will then make
                     the syntax match one of the other cases below!

              =content
                     This will make curl URL-encode the content and  pass
                     that  on.  The preceding = symbol is not included in
                     the data.

              name=content
                     This will make curl URL-encode the content part  and
                     pass that on. Note that the name part is expected to
                     be URL-encoded already.

              @filename
                     This will make curl load data from  the  given  file
                     (including  any  newlines), URL-encode that data and
                     pass it on in the POST.

              name@filename
                     This will make curl load data from  the  given  file
                     (including  any  newlines), URL-encode that data and
                     pass it on in the POST. The name part gets an  equal
                     sign  appended,  resulting  in name=urlencoded-file-
                     content. Note that the name is expected to  be  URL-
                     encoded already.

       See also -d, --data and --data-raw. Added in 7.18.0.

       -d, --data <data>
              (HTTP)  Sends  the  specified data in a POST request to the
              HTTP server, in the same way that a  browser  does  when  a
              user has filled in an HTML form and presses the submit but‐
              ton. This will cause curl to pass the data  to  the  server
              using  the  content-type application/x-www-form-urlencoded.
              Compare to -F, --form.

              --data-raw is almost the same but does not have  a  special
              interpretation  of  the  @  character.  To post data purely
              binary, you should instead use  the  --data-binary  option.
              To URL-encode the value of a form field you may use --data-
              urlencode.

              If any of these options is used more than once on the  same
              command  line,  the  data  pieces  specified will be merged
              together  with  a  separating  &-symbol.  Thus,  using  '-d
              name=daniel  -d  skill=lousy'  would  generate a post chunk
              that looks like 'name=daniel&skill=lousy'.

              If you start the data with the letter @, the rest should be
              a file name to read the data from, or - if you want curl to
              read the data from stdin. Posting data from  a  file  named
              'foobar'  would  thus be done with -d, --data @foobar. When
              -d, --data is told to read from a file like that,  carriage
              returns  and  newlines  will  be stripped out. If you don't
              want the @ character to have a special  interpretation  use
              --data-raw instead.

              See also --data-binary and --data-urlencode and --data-raw.
              This option overrides -F, --form and  -I,  --head  and  -T,
              --upload-file.

       --delegation <LEVEL>
              (GSS/kerberos)  Set  LEVEL  to  tell  the server what it is
              allowed to delegate when it comes to user credentials.

              none   Don't allow any delegation.

              policy Delegates if and only if the OK-AS-DELEGATE flag  is
                     set  in the Kerberos service ticket, which is a mat‐
                     ter of realm policy.

              always Unconditionally allow the server to delegate.

       --digest
              (HTTP) Enables  HTTP  Digest  authentication.  This  is  an
              authentication scheme that prevents the password from being
              sent over the wire in clear text. Use this  in  combination
              with  the  normal  -u,  --user  option to set user name and
              password.

              If this option is used several times, only the first one is
              used.

              See  also -u, --user and --proxy-digest and --anyauth. This
              option overrides --basic and --ntlm and --negotiate.

       --disable-eprt
              (FTP) Tell curl to disable the use of  the  EPRT  and  LPRT
              commands  when  doing  active FTP transfers. Curl will nor‐
              mally always first attempt to use EPRT,  then  LPRT  before
              using  PORT,  but  with this option, it will use PORT right
              away. EPRT and LPRT are extensions to the original FTP pro‐
              tocol,  and  may  not  work on all servers, but they enable
              more functionality in a better  way  than  the  traditional
              PORT command.

              --eprt  can  be  used  to  explicitly enable EPRT again and
              --no-eprt is an alias for --disable-eprt.

              If the server is accessed using IPv6, this option will have
              no effect as EPRT is necessary then.

              Disabling  EPRT  only  changes  the active behavior. If you
              want to switch to passive mode you  need  to  not  use  -P,
              --ftp-port or force it with --ftp-pasv.

       --disable-epsv
              (FTP)  (FTP)  Tell curl to disable the use of the EPSV com‐
              mand when doing passive FTP transfers. Curl  will  normally
              always first attempt to use EPSV before PASV, but with this
              option, it will not try using EPSV.

              --epsv can be used to  explicitly  enable  EPSV  again  and
              --no-epsv is an alias for --disable-epsv.

              If  the  server  is  an IPv6 host, this option will have no
              effect as EPSV is necessary then.

              Disabling EPSV only changes the passive  behavior.  If  you
              want  to  switch  to active mode you need to use -P, --ftp-
              port.

       -q, --disable
              If used as the first parameter on  the  command  line,  the
              curlrc  config  file will not be read and used. See the -K,
              --config for details on  the  default  config  file  search
              path.

       --disallow-username-in-url
              (HTTP) This tells curl to exit if passed a url containing a
              username.

              See also --proto. Added in 7.61.0.

       --dns-interface <interface>
              (DNS) Tell curl  to  send  outgoing  DNS  requests  through
              <interface>.  This  option  is a counterpart to --interface
              (which does not affect DNS). The supplied string must be an
              interface name (not an address).

              See  also --dns-ipv4-addr and --dns-ipv6-addr. --dns-inter‐
              face requires that the underlying libcurl was built to sup‐
              port c-ares. Added in 7.33.0.

       --dns-ipv4-addr <address>
              (DNS)  Tell  curl  to bind to <ip-address> when making IPv4
              DNS requests, so that the DNS requests originate from  this
              address. The argument should be a single IPv4 address.

              See   also   --dns-interface  and  --dns-ipv6-addr.  --dns-
              ipv4-addr requires that the underlying libcurl was built to
              support c-ares. Added in 7.33.0.

       --dns-ipv6-addr <address>
              (DNS)  Tell  curl  to bind to <ip-address> when making IPv6
              DNS requests, so that the DNS requests originate from  this
              address. The argument should be a single IPv6 address.

              See   also   --dns-interface  and  --dns-ipv4-addr.  --dns-
              ipv6-addr requires that the underlying libcurl was built to
              support c-ares. Added in 7.33.0.

       --dns-servers <addresses>
              Set  the list of DNS servers to be used instead of the sys‐
              tem default.  The list of IP addresses should be  separated
              with  commas.  Port numbers may also optionally be given as
              :<port-number> after each IP address.

              --dns-servers requires  that  the  underlying  libcurl  was
              built to support c-ares. Added in 7.33.0.

       --doh-url <URL>
              (all) Specifies which DNS-over-HTTPS (DOH) server to use to
              resolve  hostnames,  instead  of  using  the  default  name
              resolver mechanism. The URL must be HTTPS.

              If  this option is used several times, the last one will be
              used.

              Added in 7.62.0.

       -D, --dump-header <filename>
              (HTTP FTP) Write the received protocol headers to the spec‐
              ified file.

              This  option  is  handy  to  use when you want to store the
              headers that an HTTP site sends to you.  Cookies  from  the
              headers  could  then be read in a second curl invocation by
              using the -b, --cookie option! The -c, --cookie-jar  option
              is a better way to store cookies.

              If  no  headers  are  received, the use of this option will
              create an empty file.

              When used in FTP, the FTP server response lines are consid‐
              ered being "headers" and thus are saved there.

              If  this option is used several times, the last one will be
              used.

              See also -o, --output.

       --egd-file <file>
              (TLS) Specify the path name to the Entropy Gathering Daemon
              socket.  The  socket  is used to seed the random engine for
              SSL connections.

              See also --random-file.

       --engine <name>
              (TLS) Select the OpenSSL crypto engine to  use  for  cipher
              operations. Use --engine list to print a list of build-time
              supported engines. Note that  not  all  (or  none)  of  the
              engines may be available at run-time.

       --etag-compare <file>
              (HTTP) This option makes a conditional HTTP request for the
              specific ETag read from the given file by sending a  custom
              If-None-Match header using the extracted ETag.

              For correct results, make sure that specified file contains
              only a single line with a desired ETag. An  empty  file  is
              parsed as an empty ETag.

              Use  the  option  --etag-save to first save the ETag from a
              response, and then use this option  to  compare  using  the
              saved ETag in a subsequent request.

              OMPARISON:  There  are 2 types of comparison or ETags, Weak
              and Strong.  This option expects, and uses a strong compar‐
              ison.

              Added in 7.68.0.

       --etag-save <file>
              (HTTP)  This  option  saves  an  HTTP ETag to the specified
              file. Etag  is  usually  part  of  headers  returned  by  a
              request. When server sends an ETag, it must be enveloped by
              a double quote. This option extracts the ETag  without  the
              double quotes and saves it into the <file>.

              A  server  can  send a week ETag which is prefixed by "W/".
              This identifier is not considered, and only  relevant  ETag
              between quotation marks is parsed.

              It  an  ETag  wasn't  send  by  the  server or it cannot be
              parsed, and empty file is created.

              Added in 7.68.0.

       --expect100-timeout <seconds>
              (HTTP) Maximum time in seconds that you allow curl to  wait
              for  a  100-continue  response  when curl emits an Expects:
              100-continue header in its request. By  default  curl  will
              wait  one  second. This option accepts decimal values! When
              curl stops waiting, it will continue as if the response has
              been received.

              See also --connect-timeout. Added in 7.47.0.

       --fail-early
              Fail and exit on the first detected transfer error.

              When  curl  is used to do multiple transfers on the command
              line, it will attempt to operate on each given URL, one  by
              one.  By  default,  it will ignore errors if there are more
              URLs given and the last URL's success  will  determine  the
              error code curl returns. So early failures will be "hidden"
              by subsequent successful transfers.

              Using this option, curl will instead return an error on the
              first  transfer  that  fails,  independent of the amount of
              URLs that are given on  the  command  line.  This  way,  no
              transfer failures go undetected by scripts and similar.

              This option is global and does not need to be specified for
              each use of -:, --next.

              This option does not imply -f, --fail, which causes  trans‐
              fers  to fail due to the server's HTTP status code. You can
              combine the two options, however note  -f,  --fail  is  not
              global and is therefore contained by -:, --next.

              Added in 7.52.0.

       -f, --fail
              (HTTP)  Fail  silently (no output at all) on server errors.
              This is mostly done to better enable scripts etc to  better
              deal  with  failed  attempts.  In normal cases when an HTTP
              server fails to deliver a document, it returns an HTML doc‐
              ument stating so (which often also describes why and more).
              This flag will prevent curl from outputting that and return
              error 22.

              This  method is not fail-safe and there are occasions where
              non-successful response codes will slip through, especially
              when  authentication  is  involved  (response codes 401 and
              407).

       --false-start
              (TLS) Tells curl to use false start during  the  TLS  hand‐
              shake.  False start is a mode where a TLS client will start
              sending application data before verifying the server's Fin‐
              ished  message,  thus saving a round trip when performing a
              full handshake.

              This is currently only implemented in the  NSS  and  Secure
              Transport  (on  iOS  7.0  or  later, or OS X 10.9 or later)
              backends.

              Added in 7.42.0.

       --form-string <name=string>
              (HTTP SMTP IMAP) Similar to  -F,  --form  except  that  the
              value  string  for  the  named parameter is used literally.
              Leading '@' and '<' characters, and the ';type=' string  in
              the  value  have no special meaning. Use this in preference
              to -F, --form if there's any possibility  that  the  string
              value  may  accidentally trigger the '@' or '<' features of
              -F, --form.

              See also -F, --form.

       -F, --form <name=content>
              (HTTP SMTP IMAP) For HTTP protocol family, this  lets  curl
              emulate  a  filled-in  form in which a user has pressed the
              submit button. This causes curl to POST data using the Con‐
              tent-Type multipart/form-data according to RFC 2388.

              For  SMTP and IMAP protocols, this is the mean to compose a
              multipart mail message to transmit.

              This enables uploading of binary files etc.  To  force  the
              'content' part to be a file, prefix the file name with an @
              sign. To just get the content part from a file, prefix  the
              file name with the symbol <. The difference between @ and <
              is then that @ makes a file get attached in the post  as  a
              file  upload,  while  the < makes a text field and just get
              the contents for that text field from a file.

              Tell curl to read content from stdin instead of a  file  by
              using - as filename. This goes for both @ and < constructs.
              When stdin is used, the  contents  is  buffered  in  memory
              first  by  curl  to determine its size and allow a possible
              resend.  Defining a part's data from  a  named  non-regular
              file (such as a named pipe or similar) is unfortunately not
              subject to buffering and will be effectively read at trans‐
              mission  time;  since  the  full size is unknown before the
              transfer starts, such data is sent as chunks  by  HTTP  and
              rejected by IMAP.

              Example:  send  an image to an HTTP server, where 'profile'
              is the name of  the  form-field  to  which  the  file  por‐
              trait.jpg will be the input:

               curl      -F      profile=@portrait.jpg      https://exam‐
              ple.com/upload.cgi

              Example: send your name and shoe size in two text fields to
              the server:

               curl -F name=John -F shoesize=11 https://example.com/

              Example:  send  your  essay  in a text field to the server.
              Send it as a plain text field, but get the contents for  it
              from a local file:

               curl -F "story=<hugefile.txt" https://example.com/

              You  can  also  tell curl what Content-Type to use by using
              'type=', in a manner similar to:

               curl -F "web=@index.html;type=text/html" example.com

              or

               curl -F "name=daniel;type=text/foo" example.com

              You can also explicitly change the name  field  of  a  file
              upload part by setting filename=, like this:

               curl -F "file=@localfile;filename=nameinpost" example.com

              If  filename/path contains ',' or ';', it must be quoted by
              double-quotes like:

               curl   -F    "file=@\"localfile\";filename=\"nameinpost\""
              example.com

              or

               curl  -F  'file=@"localfile";filename="nameinpost"'  exam‐
              ple.com

              Note that if a filename/path is  quoted  by  double-quotes,
              any  double-quote  or backslash within the filename must be
              escaped by backslash.

              Quoting must also be applied to non-file data  if  it  con‐
              tains semicolons, leading/trailing spaces or leading double
              quotes:

               curl  -F  'colors="red;  green;   blue";type=text/x-myapp'
              example.com

              You  can  add  custom headers to the field by setting head‐
              ers=, like

                curl -F "submit=OK;headers=\"X-submit-type:  OK\""  exam‐
              ple.com

              or

                curl -F "submit=OK;headers=@headerfile" example.com

              The  headers=  keyword  may appear more that once and above
              notes about quoting apply. When headers  are  read  from  a
              file,  Empty lines and lines starting with '#' are comments
              and ignored; each header can be folded by splitting between
              two  words and starting the continuation line with a space;
              embedded carriage-returns and trailing spaces are stripped.
              Here is an example of a header file contents:

                # This file contain two headers.
                X-header-1: this is a header

                # The following header is folded.
                X-header-2: this is
                 another header

              To  support  sending multipart mail messages, the syntax is
              extended as follows:
              - name can be omitted: the equal sign is the first  charac‐
              ter of the argument,
              - if data starts with '(', this signals to start a new mul‐
              tipart: it can be followed by a content type specification.
              - a multipart can be terminated with a '=)' argument.

              Example: the following command sends an  SMTP  mime  e-mail
              consisting  in  an  inline part in two alternative formats:
              plain text and HTML. It attaches a text file:

               curl -F '=(;type=multipart/alternative' \
                       -F '=plain text message' \
                       -F '= <body>HTML message</body>;type=text/html' \
                    -F '=)' -F '=@textfile.txt' ...  smtp://example.com

              Data can be encoded for transfer using encoder=.  Available
              encodings  are  binary  and  8bit that do nothing else than
              adding the corresponding Content-Transfer-Encoding  header,
              7bit  that  only  rejects  8-bit characters with a transfer
              error,  quoted-printable  and  base64  that  encodes   data
              according  to  the  corresponding  schemes,  limiting lines
              length to 76 characters.

              Example: send multipart mail with a  quoted-printable  text
              message and a base64 attached file:

               curl -F '=text message;encoder=quoted-printable' \
                    -F   '=@localfile;encoder=base64'   ...  smtp://exam‐
              ple.com

              See further examples and details in the MANUAL.

              This option can be used multiple times.

              This option overrides -d, --data and  -I,  --head  and  -T,
              --upload-file.

       --ftp-account <data>
              (FTP) When an FTP server asks for "account data" after user
              name and password has been provided, this data is sent  off
              using the ACCT command.

              If  this option is used several times, the last one will be
              used.

              Added in 7.13.0.

       --ftp-alternative-to-user <command>
              (FTP) If authenticating with the  USER  and  PASS  commands
              fails,  send this command.  When connecting to Tumbleweed's
              Secure Transport server over FTPS using a  client  certifi‐
              cate,  using  "SITE  AUTH" will tell the server to retrieve
              the username from the certificate.

              Added in 7.15.5.

       --ftp-create-dirs
              (FTP SFTP) When an FTP or SFTP URL/operation  uses  a  path
              that  doesn't  currently  exist on the server, the standard
              behavior of curl is to fail. Using this option,  curl  will
              instead attempt to create missing directories.

              See also --create-dirs.

       --ftp-method <method>
              (FTP)  Control  what method curl should use to reach a file
              on an FTP(S) server. The method argument should be  one  of
              the following alternatives:

              multicwd
                     curl  does a single CWD operation for each path part
                     in the given URL. For deep  hierarchies  this  means
                     very  many  commands.  This  is how RFC 1738 says it
                     should be done. This is the default but the  slowest
                     behavior.

              nocwd  curl  does  no  CWD at all. curl will do SIZE, RETR,
                     STOR etc and give a full path to the server for  all
                     these commands. This is the fastest behavior.

              singlecwd
                     curl does one CWD with the full target directory and
                     then operates on the file "normally"  (like  in  the
                     multicwd case). This is somewhat more standards com‐
                     pliant than 'nocwd' but without the full penalty  of
                     'multicwd'.

       Added in 7.15.1.

       --ftp-pasv
              (FTP)  Use passive mode for the data connection. Passive is
              the internal default behavior, but using this option can be
              used to override a previous -P, --ftp-port option.

              If this option is used several times, only the first one is
              used. Undoing an enforced passive really isn't  doable  but
              you  must  then  instead enforce the correct -P, --ftp-port
              again.

              Passive mode means that curl  will  try  the  EPSV  command
              first and then PASV, unless --disable-epsv is used.

              See also --disable-epsv. Added in 7.11.0.

       -P, --ftp-port <address>
              (FTP)  Reverses  the  default initiator/listener roles when
              connecting with FTP. This  option  makes  curl  use  active
              mode.  curl  then  tells  the server to connect back to the
              client's specified address and  port,  while  passive  mode
              asks  the  server to setup an IP address and port for it to
              connect to. <address> should be one of:

              interface
                     e.g. "eth0" to specify which interface's IP  address
                     you want to use (Unix only)

              IP address
                     e.g. "192.168.10.1" to specify the exact IP address

              host name
                     e.g. "my.host.domain" to specify the machine

              -      make  curl  pick the same IP address that is already
                     used for the control connection

       If this option is used several times, the last one will  be  used.
       Disable  the  use  of PORT with --ftp-pasv. Disable the attempt to
       use the EPRT command instead of PORT by using --disable-eprt. EPRT
       is really PORT++.

       Since  7.19.5, you can append ":[start]-[end]" to the right of the
       address, to tell curl what TCP port range to use. That  means  you
       specify  a  port  range, from a lower to a higher number. A single
       number works as well, but do note that it increases  the  risk  of
       failure since the port may not be available.

       See also --ftp-pasv and --disable-eprt.

       --ftp-pret
              (FTP)  Tell  curl  to  send a PRET command before PASV (and
              EPSV). Certain FTP servers,  mainly  drftpd,  require  this
              non-standard  command  for directory listings as well as up
              and downloads in PASV mode.

              Added in 7.20.0.

       --ftp-skip-pasv-ip
              (FTP) Tell curl to not use the IP address the  server  sug‐
              gests in its response to curl's PASV command when curl con‐
              nects the data connection. Instead  curl  will  re-use  the
              same IP address it already uses for the control connection.

              This  option  has  no  effect if PORT, EPRT or EPSV is used
              instead of PASV.

              See also --ftp-pasv. Added in 7.14.2.

       --ftp-ssl-ccc-mode <active/passive>
              (FTP) Sets the CCC mode. The passive mode will not initiate
              the shutdown, but instead wait for the server to do it, and
              will not reply to the shutdown from the server. The  active
              mode  initiates the shutdown and waits for a reply from the
              server.

              See also --ftp-ssl-ccc. Added in 7.16.2.

       --ftp-ssl-ccc
              (FTP) Use  CCC  (Clear  Command  Channel)  Shuts  down  the
              SSL/TLS layer after authenticating. The rest of the control
              channel communication will be unencrypted. This allows  NAT
              routers  to follow the FTP transaction. The default mode is
              passive.

              See also --ssl and --ftp-ssl-ccc-mode. Added in 7.16.1.

       --ftp-ssl-control
              (FTP) Require SSL/TLS for the FTP login, clear  for  trans‐
              fer.   Allows secure authentication, but non-encrypted data
              transfers for efficiency.  Fails the transfer if the server
              doesn't support SSL/TLS.

              Added in 7.16.0.

       -G, --get
              When  used,  this  option will make all data specified with
              -d, --data, --data-binary or --data-urlencode to be used in
              an HTTP GET request instead of the POST request that other‐
              wise would be used. The data will be appended  to  the  URL
              with a '?' separator.

              If  used in combination with -I, --head, the POST data will
              instead be appended to the URL with a HEAD request.

              If this option is used several times, only the first one is
              used. This is because undoing a GET doesn't make sense, but
              you should then instead enforce the alternative method  you
              prefer.

       -g, --globoff
              This  option  switches  off the "URL globbing parser". When
              you set this option, you can specify URLs that contain  the
              letters  {}[] without having them being interpreted by curl
              itself. Note that these letters are not  normal  legal  URL
              contents  but  they  should be encoded according to the URI
              standard.

       --happy-eyeballs-timeout-ms <milliseconds>
              Happy eyeballs is an algorithm that attempts to connect  to
              both  IPv4 and IPv6 addresses for dual-stack hosts, prefer‐
              ring IPv6 first for the number of milliseconds. If the IPv6
              address cannot be connected to within that time then a con‐
              nection attempt is made to the IPv4  address  in  parallel.
              The  first  connection to be established is the one that is
              used.

              The range of suggested useful values is limited. Happy Eye‐
              balls  RFC  6555  says  "It  is RECOMMENDED that connection
              attempts be paced 150-250 ms apart to balance human factors
              against  network  load."  libcurl currently defaults to 200
              ms. Firefox and Chrome currently default to 300 ms.

              If this option is used several times, the last one will  be
              used.

              Added in 7.59.0.

       --haproxy-protocol
              (HTTP)  Send  a  HAProxy  PROXY  protocol  v1 header at the
              beginning of the connection. This is used by some load bal‐
              ancers and reverse proxies to indicate the client's true IP
              address and port.

              This option is primarily useful when sending test  requests
              to a service that expects this header.

              Added in 7.60.0.

       -I, --head
              (HTTP  FTP  FILE) Fetch the headers only! HTTP-servers fea‐
              ture the command HEAD which this uses to  get  nothing  but
              the header of a document. When used on an FTP or FILE file,
              curl displays the file  size  and  last  modification  time
              only.

       -H, --header <header/@file>
              (HTTP)  Extra header to include in the request when sending
              HTTP to a server. You may specify any number of extra head‐
              ers.  Note  that if you should add a custom header that has
              the same name as one of the internal ones curl  would  use,
              your  externally  set  header  will  be used instead of the
              internal one. This allows you to make even  trickier  stuff
              than  curl would normally do. You should not replace inter‐
              nally set  headers  without  knowing  perfectly  well  what
              you're  doing.  Remove  an  internal  header  by  giving  a
              replacement without content on the right side of the colon,
              as  in:  -H "Host:". If you send the custom header with no-
              value then its header must be terminated with a  semicolon,
              such as -H "X-Custom-Header;" to send "X-Custom-Header:".

              curl  will  make  sure  that each header you add/replace is
              sent with the proper end-of-line marker,  you  should  thus
              not  add  that  as a part of the header content: do not add
              newlines or carriage returns, they will only mess things up
              for you.

              Starting  in  7.55.0,  this  option can take an argument in
              @filename style, which then adds a header for each line  in
              the  input  file.  Using  @- will make curl read the header
              file from stdin.

              See also the -A, --user-agent and -e, --referer options.

              Starting in 7.37.0, you need --proxy-header to send  custom
              headers intended for a proxy.

              Example:

               curl -H "X-First-Name: Joe" http://example.com/

              WARNING:  headers  set  with this option will be set in all
              requests - even after redirects  are  followed,  like  when
              told with -L, --location. This can lead to the header being
              sent to other hosts than the original  host,  so  sensitive
              headers should be used with caution combined with following
              redirects.

              This   option   can   be    used    multiple    times    to
              add/replace/remove multiple headers.

       -h, --help
              Usage  help.  This  lists  all current command line options
              with a short description.

       --hostpubmd5 <md5>
              (SFTP SCP) Pass a string containing 32 hexadecimal  digits.
              The string should be the 128 bit MD5 checksum of the remote
              host's public key, curl will refuse the connection with the
              host unless the md5sums match.

              Added in 7.17.1.

       --http0.9
              (HTTP)  Tells  curl  to  be  fine  with  HTTP  version  0.9
              response.

              HTTP/0.9 is a completely headerless response and  therefore
              you  can  also  connect  with  this to non-HTTP servers and
              still get a response since curl will  simply  transparently
              downgrade - if allowed.

              Since curl 7.66.0, HTTP/0.9 is disabled by default.

       -0, --http1.0
              (HTTP)  Tells curl to use HTTP version 1.0 instead of using
              its internally preferred HTTP version.

              This option overrides --http1.1 and --http2.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1.

              This option overrides -0, --http1.0 and --http2.  Added  in
              7.33.0.

       --http2-prior-knowledge
              (HTTP)  Tells curl to issue its non-TLS HTTP requests using
              HTTP/2 without HTTP/1.1 Upgrade. It requires  prior  knowl‐
              edge  that  the server supports HTTP/2 straight away. HTTPS
              requests will still do HTTP/2 the standard way with negoti‐
              ated protocol version in the TLS handshake.

              --http2-prior-knowledge   requires   that   the  underlying
              libcurl was built to support HTTP/2. This option  overrides
              --http1.1 and -0, --http1.0 and --http2. Added in 7.49.0.

       --http2
              (HTTP) Tells curl to use HTTP version 2.

              See  also  --http1.1 and --http3. --http2 requires that the
              underlying libcurl was built to support HTTP/2. This option
              overrides  --http1.1  and  -0, --http1.0 and --http2-prior-
              knowledge. Added in 7.33.0.

       --http3
              (HTTP) WARNING: this option is experimental. Do not use  in
              production.

              Tells  curl  to use HTTP version 3 directly to the host and
              port number used in the URL. A  normal  HTTP/3  transaction
              will be done to a host and then get redirected via Alt-SVc,
              but this option allows a user to circumvent that  when  you
              know  that  the  target speaks HTTP/3 on the given host and
              port.

              This option will make curl fail if a QUIC connection cannot
              be established, it cannot fall back to a lower HTTP version
              on its own.

              See also --http1.1 and --http2. --http3 requires  that  the
              underlying libcurl was built to support HTTP/3. This option
              overrides --http1.1  and  -0,  --http1.0  and  --http2  and
              --http2-prior-knowledge. Added in 7.66.0.

       --ignore-content-length
              (FTP HTTP) For HTTP, Ignore the Content-Length header. This
              is particularly useful  for  servers  running  Apache  1.x,
              which will report incorrect Content-Length for files larger
              than 2 gigabytes.

              For FTP (since 7.46.0), skip the RETR command to figure out
              the size before downloading a file.

       -i, --include
              Include  the  HTTP response headers in the output. The HTTP
              response headers can include things like server name, cook‐
              ies, date of the document, HTTP version and more...

              To  view  the  request  headers, consider the -v, --verbose
              option.

              See also -v, --verbose.

       -k, --insecure
              (TLS) By default, every SSL connection curl makes is  veri‐
              fied  to  be secure. This option allows curl to proceed and
              operate even for server  connections  otherwise  considered
              insecure.

              The  server  connection  is  verified  by  making  sure the
              server's certificate contains the right name  and  verifies
              successfully using the cert store.

              See this online resource for further details:
               https://curl.haxx.se/docs/sslcerts.html

              See also --proxy-insecure and --cacert.

       --interface <name>

              Perform  an  operation using a specified interface. You can
              enter interface name, IP address or host name.  An  example
              could look like:

               curl --interface eth0:1 https://www.example.com/

              If  this option is used several times, the last one will be
              used.

              On Linux it can be used to specify a VRF,  but  the  binary
              needs to either have CAP_NET_RAW or to be run as root. More
              information    about    Linux     VRF:     https://www.ker‐
              nel.org/doc/Documentation/networking/vrf.txt

              See also --dns-interface.

       -4, --ipv4
              This  option  tells curl to resolve names to IPv4 addresses
              only, and not for example try IPv6.

              See also --http1.1 and --http2. This option  overrides  -6,
              --ipv6.

       -6, --ipv6
              This  option  tells curl to resolve names to IPv6 addresses
              only, and not for example try IPv4.

              See also --http1.1 and --http2. This option  overrides  -4,
              --ipv4.

       -j, --junk-session-cookies
              (HTTP) When curl is told to read cookies from a given file,
              this option will make it  discard  all  "session  cookies".
              This  will  basically have the same effect as if a new ses‐
              sion is started. Typical browsers  always  discard  session
              cookies when they're closed down.

              See also -b, --cookie and -c, --cookie-jar.

       --keepalive-time <seconds>
              This option sets the time a connection needs to remain idle
              before sending keepalive probes and the time between  indi‐
              vidual keepalive probes. It is currently effective on oper‐
              ating systems offering the TCP_KEEPIDLE  and  TCP_KEEPINTVL
              socket options (meaning Linux, recent AIX, HP-UX and more).
              This option has no effect if --no-keepalive is used.

              If this option is used several times, the last one will  be
              used. If unspecified, the option defaults to 60 seconds.

              Added in 7.18.0.

       --key-type <type>
              (TLS)  Private key file type. Specify which type your --key
              provided private key is. DER, PEM, and ENG  are  supported.
              If not specified, PEM is assumed.

              If  this option is used several times, the last one will be
              used.

       --key <key>
              (TLS SSH) Private key file name. Allows you to provide your
              private  key  in this separate file. For SSH, if not speci‐
              fied,  curl  tries  the  following  candidates  in   order:
              '~/.ssh/id_rsa', '~/.ssh/id_dsa', './id_rsa', './id_dsa'.

              If  curl  is  built against OpenSSL library, and the engine
              pkcs11 is available, then a PKCS#11 URI (RFC 7512)  can  be
              used  to specify a private key located in a PKCS#11 device.
              A string beginning with "pkcs11:" will be interpreted as  a
              PKCS#11  URI.  If  a  PKCS#11  URI  is  provided,  then the
              --engine option will be set as "pkcs11" if  none  was  pro‐
              vided  and  the  --key-type  option will be set as "ENG" if
              none was provided.

              If this option is used several times, the last one will  be
              used.

       --krb <level>
              (FTP)  Enable  Kerberos  authentication  and use. The level
              must be entered and should be one of 'clear', 'safe', 'con‐
              fidential',  or  'private'.  Should you use a level that is
              not one of these, 'private' will instead be used.

              If this option is used several times, the last one will  be
              used.

              --krb  requires  that  the  underlying libcurl was built to
              support Kerberos.

       --libcurl <file>
              Append this option to any ordinary curl command  line,  and
              you  will  get a libcurl-using C source code written to the
              file that does the equivalent  of  what  your  command-line
              operation does!

              If  this  option is used several times, the last given file
              name will be used.

              Added in 7.16.1.

       --limit-rate <speed>
              Specify the maximum transfer rate you want curl  to  use  -
              for  both  downloads and uploads. This feature is useful if
              you have a limited pipe and you'd like your transfer not to
              use your entire bandwidth. To make it slower than it other‐
              wise would be.

              The given speed is measured in bytes/second, unless a  suf‐
              fix  is appended.  Appending 'k' or 'K' will count the num‐
              ber as kilobytes, 'm' or 'M' makes it megabytes, while  'g'
              or 'G' makes it gigabytes. Examples: 200K, 3m and 1G.

              If  you  also use the -Y, --speed-limit option, that option
              will take precedence and might  cripple  the  rate-limiting
              slightly, to help keeping the speed-limit logic working.

              If  this option is used several times, the last one will be
              used.

       -l, --list-only
              (FTP POP3) (FTP) When listing an FTP directory, this switch
              forces  a  name-only view. This is especially useful if the
              user wants to machine-parse the contents of an  FTP  direc‐
              tory since the normal directory view doesn't use a standard
              look or format. When used like this, the  option  causes  a
              NLST command to be sent to the server instead of LIST.

              Note: Some FTP servers list only files in their response to
              NLST; they do  not  include  sub-directories  and  symbolic
              links.

              (POP3)  When  retrieving  a  specific email from POP3, this
              switch forces a LIST command to  be  performed  instead  of
              RETR.  This is particularly useful if the user wants to see
              if a specific message id exists on the server and what size
              it is.

              Note:  When combined with -X, --request, this option can be
              used to send an UIDL command instead, so the user  may  use
              the  email's  unique identifier rather than it's message id
              to make the request.

              Added in 7.21.5.

       --local-port <num/range>
              Set a preferred single number or range (FROM-TO)  of  local
              port  numbers to use for the connection(s).  Note that port
              numbers by nature are a scarce resource that will  be  busy
              at  times  so  setting  this  range to something too narrow
              might cause unnecessary connection setup failures.

              Added in 7.15.2.

       --location-trusted
              (HTTP) Like -L, --location, but will allow sending the name
              + password to all hosts that the site may redirect to. This
              may or may not introduce a  security  breach  if  the  site
              redirects you to a site to which you'll send your authenti‐
              cation info (which is plaintext in the case of  HTTP  Basic
              authentication).

              See also -u, --user.

       -L, --location
              (HTTP)  If  the  server reports that the requested page has
              moved to a different location (indicated with  a  Location:
              header and a 3XX response code), this option will make curl
              redo the request on the new place. If  used  together  with
              -i,  --include  or  -I,  --head, headers from all requested
              pages will be shown. When authentication is used, curl only
              sends  its  credentials  to the initial host. If a redirect
              takes curl to a different host, it won't be able to  inter‐
              cept  the user+password. See also --location-trusted on how
              to change this. You can limit the amount  of  redirects  to
              follow by using the --max-redirs option.

              When  curl follows a redirect and if the request is a POST,
              it will do the following request with a  GET  if  the  HTTP
              response was 301, 302, or 303. If the response code was any
              other 3xx code, curl will  re-send  the  following  request
              using the same unmodified method.

              You  can tell curl to not change POST requests to GET after
              a 30x response by using the  dedicated  options  for  that:
              --post301, --post302 and --post303.

              The method set with -X, --request overrides the method curl
              would otherwise select to use.

       --login-options <options>
              (IMAP POP3 SMTP) Specify the login options  to  use  during
              server authentication.

              You  can use the login options to specify protocol specific
              options that may be used during authentication. At  present
              only  IMAP,  POP3  and SMTP support login options. For more
              information about the login options please  see  RFC  2384,
              RFC 5092 and IETF draft draft-earhart-url-smtp-00.txt

              If  this option is used several times, the last one will be
              used.

              Added in 7.34.0.

       --mail-auth <address>
              (SMTP) Specify a single address. This will be used to spec‐
              ify  the  authentication  address (identity) of a submitted
              message that is being relayed to another server.

              See also --mail-rcpt and --mail-from. Added in 7.25.0.

       --mail-from <address>
              (SMTP) Specify a single address that the given mail  should
              get sent from.

              See also --mail-rcpt and --mail-auth. Added in 7.20.0.

       --mail-rcpt-allowfails
              (SMTP) When sending data to multiple recipients, by default
              curl will abort SMTP conversation if at least  one  of  the
              recipients causes RCPT TO command to return an error.

              The default behavior can be changed by passing --mail-rcpt-
              allowfails command-line option which will make curl  ignore
              errors and proceed with the remaining valid recipients.

              In  case when all recipients cause RCPT TO command to fail,
              curl will abort SMTP  conversation  and  return  the  error
              received  from  to  the  last  RCPT  TO  command.  Added in
              7.69.0.

       --mail-rcpt <address>
              (SMTP) Specify a single address, user name or mailing  list
              name.  Repeat this option several times to send to multiple
              recipients.

              When performing a mail transfer, the recipient should spec‐
              ify a valid email address to send the mail to.

              When performing an address verification (VRFY command), the
              recipient should be specified as the user name or user name
              and  domain  (as  per  Section  3.5  of RFC5321). (Added in
              7.34.0)

              When performing a mailing list expand (EXPN  command),  the
              recipient  should be specified using the mailing list name,
              such as "Friends" or "London-Office".  (Added in 7.34.0)

              Added in 7.20.0.

       -M, --manual
              Manual. Display the huge help text.

       --max-filesize <bytes>
              Specify the maximum size (in bytes) of a file to  download.
              If the file requested is larger than this value, the trans‐
              fer will not start and curl will return with exit code 63.

              A size modifier may be used. For example, Appending 'k'  or
              'K' will count the number as kilobytes, 'm' or 'M' makes it
              megabytes, while 'g' or 'G' makes it  gigabytes.  Examples:
              200K, 3m and 1G. (Added in 7.58.0)

              NOTE:  The file size is not always known prior to download,
              and for such files this option has no effect  even  if  the
              file  transfer  ends up being larger than this given limit.
              This concerns both FTP and HTTP transfers.

              See also --limit-rate.

       --max-redirs <num>
              (HTTP)  Set  maximum   number   of   redirection-followings
              allowed.  When  -L,  --location is used, is used to prevent
              curl from following redirections too much. By default,  the
              limit  is  set to 50 redirections. Set this option to -1 to
              make it unlimited.

              If this option is used several times, the last one will  be
              used.

       -m, --max-time <seconds>
              Maximum  time in seconds that you allow the whole operation
              to take.  This is useful for  preventing  your  batch  jobs
              from  hanging for hours due to slow networks or links going
              down.  Since 7.32.0, this option  accepts  decimal  values,
              but  the  actual  timeout  will decrease in accuracy as the
              specified timeout increases in decimal precision.

              If this option is used several times, the last one will  be
              used.

              See also --connect-timeout.

       --metalink
              This  option can tell curl to parse and process a given URI
              as Metalink file (both version 3 and 4 (RFC 5854) are  sup‐
              ported)  and  make  use  of  the  mirrors listed within for
              failover if there are errors (such as the  file  or  server
              not  being  available). It will also verify the hash of the
              file after the download completes. The Metalink file itself
              is downloaded and processed in memory and not stored in the
              local file system.

              Example to use a remote Metalink file:

               curl --metalink http://www.example.com/example.metalink

              To use a Metalink file in the local file system,  use  FILE
              protocol (file://):

               curl --metalink file://example.metalink

              Please  note that if FILE protocol is disabled, there is no
              way to use a local Metalink file at the time of this  writ‐
              ing.  Also  note  that  if --metalink and -i, --include are
              used together, --include will be ignored. This  is  because
              including  headers  in  the  response  will  break Metalink
              parser  and  if  the  headers  are  included  in  the  file
              described in Metalink file, hash check will fail.

              --metalink  requires  that the underlying libcurl was built
              to support metalink. Added in 7.27.0.

       --negotiate
              (HTTP) Enables Negotiate (SPNEGO) authentication.

              This option requires a library built with GSS-API  or  SSPI
              support.  Use  -V,  --version  to see if your curl supports
              GSS-API/SSPI or SPNEGO.

              When using this option, you must also provide  a  fake  -u,
              --user option to activate the authentication code properly.
              Sending a '-u :' is enough as the user  name  and  password
              from the -u, --user option aren't actually used.

              If this option is used several times, only the first one is
              used.

              See also --basic and --ntlm and --anyauth and --proxy-nego‐
              tiate.

       --netrc-file <filename>
              This option is similar to -n, --netrc, except that you pro‐
              vide the path (absolute or relative) to the netrc file that
              curl  should  use.  You can only specify one netrc file per
              invocation. If several --netrc-file options  are  provided,
              the last one will be used.

              It will abide by --netrc-optional if specified.

              This option overrides -n, --netrc. Added in 7.21.5.

       --netrc-optional
              Very  similar  to  -n,  --netrc,  but this option makes the
              .netrc usage optional and not mandatory as the -n,  --netrc
              option does.

              See also --netrc-file. This option overrides -n, --netrc.

       -n, --netrc
              Makes  curl scan the .netrc (_netrc on Windows) file in the
              user's home directory for login name and password. This  is
              typically  used  for  FTP  on Unix. If used with HTTP, curl
              will enable user authentication. See  netrc(5)  ftp(1)  for
              details  on the file format. Curl will not complain if that
              file doesn't have the right permissions (it should  not  be
              either  world- or group-readable). The environment variable
              "HOME" is used to find the home directory.

              A quick and very simple example of how to setup a .netrc to
              allow  curl to FTP to the machine host.domain.com with user
              name 'myself' and password 'secret' should look similar to:

              machine host.domain.com login myself password secret

       -:, --next
              Tells curl to use a separate operation  for  the  following
              URL and associated options. This allows you to send several
              URL requests, each with their  own  specific  options,  for
              example,  such  as  different user names or custom requests
              for each.

              -:, --next will reset all local  options  and  only  global
              ones  will  have their values survive over to the operation
              following  the  -:,  --next  instruction.  Global   options
              include  -v,  --verbose, --trace, --trace-ascii and --fail-
              early.

              For example, you can do both a GET and a POST in  a  single
              command line:

               curl www1.example.com --next -d postthis www2.example.com

              Added in 7.36.0.

       --no-alpn
              (HTTPS)  Disable the ALPN TLS extension. ALPN is enabled by
              default if libcurl was built with an SSL library that  sup‐
              ports  ALPN. ALPN is used by a libcurl that supports HTTP/2
              to negotiate HTTP/2 support with the  server  during  https
              sessions.

              See  also --no-npn and --http2. --no-alpn requires that the
              underlying libcurl was  built  to  support  TLS.  Added  in
              7.36.0.

       -N, --no-buffer
              Disables the buffering of the output stream. In normal work
              situations, curl will use a standard buffered output stream
              that  will  have the effect that it will output the data in
              chunks, not necessarily  exactly  when  the  data  arrives.
              Using this option will disable that buffering.

              Note  that  this is the negated option name documented. You
              can thus use --buffer to enforce the buffering.

       --no-keepalive
              Disables the use of keepalive messages on the  TCP  connec‐
              tion. curl otherwise enables them by default.

              Note  that  this is the negated option name documented. You
              can thus use --keepalive to enforce keepalive.

       --no-npn
              (HTTPS) Disable the NPN TLS extension. NPN  is  enabled  by
              default  if libcurl was built with an SSL library that sup‐
              ports NPN. NPN is used by a libcurl that supports HTTP/2 to
              negotiate  HTTP/2 support with the server during https ses‐
              sions.

              See also --no-alpn and --http2. --no-npn requires that  the
              underlying  libcurl  was  built  to  support  TLS. Added in
              7.36.0.

       --no-progress-meter
              Option to switch off the progress meter output without mut‐
              ing  or  otherwise affecting warning and informational mes‐
              sages like -s, --silent does.

              Note that this is the negated option name  documented.  You
              can  thus use --progress-meter to enable the progress meter
              again.

              See also -v, --verbose and -s, --silent. Added in 7.67.0.

       --no-sessionid
              (TLS) Disable curl's use of  SSL  session-ID  caching.   By
              default  all  transfers are done using the cache. Note that
              while nothing should ever get hurt by attempting  to  reuse
              SSL  session-IDs,  there  seem to be broken SSL implementa‐
              tions in the wild that may require you to disable  this  in
              order for you to succeed.

              Note  that  this is the negated option name documented. You
              can thus use --sessionid to enforce session-ID caching.

              Added in 7.16.0.

       --noproxy <no-proxy-list>
              Comma-separated list of hosts which do not use a proxy,  if
              one  is specified.  The only wildcard is a single * charac‐
              ter, which matches all hosts, and effectively disables  the
              proxy. Each name in this list is matched as either a domain
              which contains the hostname, or the  hostname  itself.  For
              example, local.com would match local.com, local.com:80, and
              www.local.com, but not www.notlocal.com.

              Since 7.53.0, This option overrides the  environment  vari‐
              ables  that  disable  the  proxy. If there's an environment
              variable disabling a proxy, you can set noproxy list to  ""
              to override it.

              Added in 7.19.4.

       --ntlm-wb
              (HTTP) Enables NTLM much in the style --ntlm does, but hand
              over the authentication to  the  separate  binary  ntlmauth
              application that is executed when needed.

              See also --ntlm and --proxy-ntlm.

       --ntlm (HTTP) Enables NTLM authentication. The NTLM authentication
              method was designed by Microsoft and is  used  by  IIS  web
              servers.  It  is a proprietary protocol, reverse-engineered
              by clever people and implemented in  curl  based  on  their
              efforts.  This kind of behavior should not be endorsed, you
              should encourage everyone who uses NTLM to switch to a pub‐
              lic  and  documented authentication method instead, such as
              Digest.

              If you want to enable NTLM for your  proxy  authentication,
              then use --proxy-ntlm.

              If this option is used several times, only the first one is
              used.

              See also --proxy-ntlm. --ntlm requires that the  underlying
              libcurl  was  built  to  support TLS. This option overrides
              --basic and --negotiate and --digest and --anyauth.

       --oauth2-bearer <token>
              (IMAP POP3 SMTP HTTP) Specify the Bearer  Token  for  OAUTH
              2.0 server authentication. The Bearer Token is used in con‐
              junction with the user name which can be specified as  part
              of the --url or -u, --user options.

              The  Bearer  Token and user name are formatted according to
              RFC 6750.

              If this option is used several times, the last one will  be
              used.

       -o, --output <file>
              Write  output to <file> instead of stdout. If you are using
              {} or [] to fetch multiple documents, you can use '#'  fol‐
              lowed  by  a  number in the <file> specifier. That variable
              will be replaced with the current string for the URL  being
              fetched. Like in:

               curl http://{one,two}.example.com -o "file_#1.txt"

              or use several variables like:

               curl http://{site,host}.host[1-5].com -o "#1_#2"

              You may use this option as many times as the number of URLs
              you have. For example, if you specify two URLs on the  same
              command line, you can use it like this:

                curl -o aa example.com -o bb example.net

              and  the  order of the -o options and the URLs doesn't mat‐
              ter, just that the first -o is for the first URL and so on,
              so the above command line can also be written as

                curl example.com example.net -o aa -o bb

              See  also  the  --create-dirs  option  to  create the local
              directories dynamically. Specifying the output  as  '-'  (a
              single dash) will force the output to be done to stdout.

              See  also  -O,  --remote-name and --remote-name-all and -J,
              --remote-header-name.

       --parallel-immediate
              When doing parallel transfers, this  option  will  instruct
              curl  that  it should rather prefer opening up more connec‐
              tions in parallel at once rather than waiting to see if new
              transfers  can  be  added as multiplexed streams on another
              connection.

              See  also  -Z,  --parallel  and  --parallel-max.  Added  in
              7.68.0.

       --parallel-max
              When  asked to do parallel transfers, using -Z, --parallel,
              this option controls the maximum amount of transfers to  do
              simultaneously.

              The default is 50.

              See also -Z, --parallel. Added in 7.66.0.

       -Z, --parallel
              Makes curl perform its transfers in parallel as compared to
              the regular serial manner.

              Added in 7.66.0.

       --pass <phrase>
              (SSH TLS) Passphrase for the private key

              If this option is used several times, the last one will  be
              used.

       --path-as-is
              Tell  curl  to  not  handle sequences of /../ or /./ in the
              given URL path. Normally curl will  squash  or  merge  them
              according to standards but with this option set you tell it
              not to do that.

              Added in 7.42.0.

       --pinnedpubkey <hashes>
              (TLS) Tells curl to use the specified public key  file  (or
              hashes)  to  verify  the peer. This can be a path to a file
              which contains a single public key in PEM or DER format, or
              any  number  of  base64  encoded  sha256 hashes preceded by
              ´sha256//´ and separated by ´;´

              When negotiating a TLS or SSL connection, the server  sends
              a  certificate  indicating  its  identity.  A public key is
              extracted from this certificate and if it does not  exactly
              match  the  public  key  provided to this option, curl will
              abort the connection before sending or receiving any data.

              PEM/DER support:
                7.39.0: OpenSSL, GnuTLS and GSKit
                7.43.0: NSS and wolfSSL
                7.47.0: mbedtls sha256 support:
                7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL
                7.47.0: mbedtls Other SSL backends not supported.

              If this option is used several times, the last one will  be
              used.

       --post301
              (HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert
              POST requests into GET requests when following a 301  redi‐
              rection.   The  non-RFC  behaviour  is  ubiquitous  in  web
              browsers, so curl does the conversion by default  to  main‐
              tain  consistency.  However, a server may require a POST to
              remain a POST after such  a  redirection.  This  option  is
              meaningful only when using -L, --location.

              See  also --post302 and --post303 and -L, --location. Added
              in 7.17.1.

       --post302
              (HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert
              POST  requests into GET requests when following a 302 redi‐
              rection.  The  non-RFC  behaviour  is  ubiquitous  in   web
              browsers,  so  curl does the conversion by default to main‐
              tain consistency. However, a server may require a  POST  to
              remain  a  POST  after  such  a redirection. This option is
              meaningful only when using -L, --location.

              See also --post301 and --post303 and -L, --location.  Added
              in 7.19.1.

       --post303
              (HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert
              POST requests into GET requests when following 303 redirec‐
              tions. A server may require a POST to remain a POST after a
              303 redirection. This option is meaningful only when  using
              -L, --location.

              See  also --post302 and --post301 and -L, --location. Added
              in 7.26.0.

       --preproxy [protocol://]host[:port]
              Use the specified SOCKS proxy before connecting to an  HTTP
              or HTTPS -x, --proxy. In such a case curl first connects to
              the SOCKS proxy and then connects (through  SOCKS)  to  the
              HTTP or HTTPS proxy. Hence pre proxy.

              The pre proxy string should be specified with a protocol://
              prefix  to  specify  alternative   proxy   protocols.   Use
              socks4://,  socks4a://,  socks5:// or socks5h:// to request
              the specific SOCKS version to be used. No  protocol  speci‐
              fied will make curl default to SOCKS4.

              If the port number is not specified in the proxy string, it
              is assumed to be 1080.

              User and password that  might  be  provided  in  the  proxy
              string  are URL decoded by curl. This allows you to pass in
              special characters such as @ by using  %40  or  pass  in  a
              colon with %3a.

              If  this option is used several times, the last one will be
              used.

              Added in 7.52.0.

       -#, --progress-bar
              Make curl display transfer progress as  a  simple  progress
              bar instead of the standard, more informational, meter.

              This  progress  bar  draws  a single line of '#' characters
              across the screen and shows a percentage  if  the  transfer
              size  is  known.  For transfers without a known size, there
              will be space ship (-=o=-) that moves back  and  forth  but
              only  while data is being transferred, with a set of flying
              hash sign symbols on top.

       --proto-default <protocol>
              Tells curl to use protocol for any  URL  missing  a  scheme
              name.

              Example:

               curl --proto-default https ftp.mozilla.org

              An   unknown   or   unsupported   protocol   causes   error
              CURLE_UNSUPPORTED_PROTOCOL (1).

              This option does not  change  the  default  proxy  protocol
              (http).

              Without  this  option  curl would make a guess based on the
              host, see --url for details.

              Added in 7.45.0.

       --proto-redir <protocols>
              Tells curl to limit what protocols it may use on  redirect.
              Protocols  denied  by  --proto  are  not overridden by this
              option. See --proto for how protocols are represented.

              Example, allow only HTTP and HTTPS on redirect:

               curl --proto-redir -all,http,https http://example.com

              By default curl will allow HTTP, HTTPS, FTP and FTPS on re‐
              direct (7.65.2).  Older versions of curl allowed all proto‐
              cols on redirect except several disabled for security  rea‐
              sons:  Since  7.19.4  FILE  and SCP are disabled, and since
              7.40.0 SMB and SMBS are also disabled.  Specifying  all  or
              +all  enables  all  protocols  on redirect, including those
              disabled for security.

              Added in 7.20.2.

       --proto <protocols>
              Tells curl to limit what protocols it may use in the trans‐
              fer. Protocols are evaluated left to right, are comma sepa‐
              rated, and are each a protocol name  or  'all',  optionally
              prefixed  by  zero  or  more modifiers. Available modifiers
              are:

              +  Permit this protocol in addition  to  protocols  already
                 permitted (this is the default if no modifier is used).

              -  Deny  this protocol, removing it from the list of proto‐
                 cols already permitted.

              =  Permit only this protocol  (ignoring  the  list  already
                 permitted), though subject to later modification by sub‐
                 sequent entries in the comma separated list.

              For example:

              --proto -ftps  uses the  default  protocols,  but  disables
                             ftps

              --proto -all,https,+http
                             only enables http and https

              --proto =http,https
                             also only enables http and https

       Unknown protocols produce a warning. This allows scripts to safely
       rely on being able to  disable  potentially  dangerous  protocols,
       without  relying  upon  support for that protocol being built into
       curl to avoid an error.

       This option can be used multiple times, in which case  the  effect
       is  the  same  as concatenating the protocols into one instance of
       the option.

       See also --proto-redir and --proto-default. Added in 7.20.2.

       --proxy-anyauth
              Tells curl to pick a suitable  authentication  method  when
              communicating  with  the given HTTP proxy. This might cause
              an extra request/response round-trip.

              See also -x, --proxy and --proxy-basic and  --proxy-digest.
              Added in 7.13.2.

       --proxy-basic
              Tells  curl  to use HTTP Basic authentication when communi‐
              cating with the given proxy. Use --basic for enabling  HTTP
              Basic  with a remote host. Basic is the default authentica‐
              tion method curl uses with proxies.

              See also  -x,  --proxy  and  --proxy-anyauth  and  --proxy-
              digest.

       --proxy-cacert <file>
              Same as --cacert but used in HTTPS proxy context.

              See  also  --proxy-capath and --cacert and --capath and -x,
              --proxy. Added in 7.52.0.

       --proxy-capath <dir>
              Same as --capath but used in HTTPS proxy context.

              See also --proxy-cacert and -x, --proxy and --capath. Added
              in 7.52.0.

       --proxy-cert-type <type>
              Same as --cert-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-cert <cert[:passwd]>
              Same as -E, --cert but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-ciphers <list>
              Same as --ciphers but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-crlfile <file>
              Same as --crlfile but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-digest
              Tells  curl to use HTTP Digest authentication when communi‐
              cating with the given proxy. Use --digest for enabling HTTP
              Digest with a remote host.

              See also -x, --proxy and --proxy-anyauth and --proxy-basic.

       --proxy-header <header/@file>
              (HTTP)  Extra header to include in the request when sending
              HTTP to a proxy. You may specify any number of extra  head‐
              ers.  This  is the equivalent option to -H, --header but is
              for proxy communication only like in CONNECT requests  when
              you  want  a  separate  header sent to the proxy to what is
              sent to the actual remote host.

              curl will make sure that each  header  you  add/replace  is
              sent  with  the  proper end-of-line marker, you should thus
              not add that as a part of the header content:  do  not  add
              newlines or carriage returns, they will only mess things up
              for you.

              Headers specified with this option will not be included  in
              requests that curl knows will not be sent to a proxy.

              Starting  in  7.55.0,  this  option can take an argument in
              @filename style, which then adds a header for each line  in
              the  input  file.  Using  @- will make curl read the header
              file from stdin.

              This   option   can   be    used    multiple    times    to
              add/replace/remove multiple headers.

              Added in 7.37.0.

       --proxy-insecure
              Same as -k, --insecure but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key-type <type>
              Same as --key-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key <key>
              Same as --key but used in HTTPS proxy context.

       --proxy-negotiate
              Tells  curl  to  use HTTP Negotiate (SPNEGO) authentication
              when communicating with the given  proxy.  Use  --negotiate
              for enabling HTTP Negotiate (SPNEGO) with a remote host.

              See   also  --proxy-anyauth  and  --proxy-basic.  Added  in
              7.17.1.

       --proxy-ntlm
              Tells curl to use HTTP NTLM authentication when communicat‐
              ing with the given proxy. Use --ntlm for enabling NTLM with
              a remote host.

              See also --proxy-negotiate and --proxy-anyauth.

       --proxy-pass <phrase>
              Same as --pass but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-pinnedpubkey <hashes>
              (TLS) Tells curl to use the specified public key  file  (or
              hashes)  to  verify the proxy. This can be a path to a file
              which contains a single public key in PEM or DER format, or
              any  number  of  base64  encoded  sha256 hashes preceded by
              ´sha256//´ and separated by ´;´

              When negotiating a TLS or SSL connection, the server  sends
              a  certificate  indicating  its  identity.  A public key is
              extracted from this certificate and if it does not  exactly
              match  the  public  key  provided to this option, curl will
              abort the connection before sending or receiving any data.

              If this option is used several times, the last one will  be
              used.

       --proxy-service-name <name>
              This option allows you to change the service name for proxy
              negotiation.

              Added in 7.43.0.

       --proxy-ssl-allow-beast
              Same as --ssl-allow-beast but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tls13-ciphers <ciphersuite list>
              (TLS) Specifies which cipher suites to use in  the  connec‐
              tion  to  your  HTTPS proxy when it negotiates TLS 1.3. The
              list of ciphers suites must specify valid ciphers. Read  up
              on TLS 1.3 cipher suite details on this URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              This  option  is  currently used only when curl is built to
              use OpenSSL 1.1.1 or later. If you are  using  a  different
              SSL  backend  you  can try setting TLS 1.3 cipher suites by
              using the --proxy-ciphers option.

              If this option is used several times, the last one will  be
              used.

       --proxy-tlsauthtype <type>
              Same as --tlsauthtype but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlspassword <string>
              Same as --tlspassword but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsuser <name>
              Same as --tlsuser but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsv1
              Same as -1, --tlsv1 but used in HTTPS proxy context.

              Added in 7.52.0.

       -U, --proxy-user <user:password>
              Specify the user name and password to use for proxy authen‐
              tication.

              If you use a Windows SSPI-enabled curl binary and do either
              Negotiate  or NTLM authentication then you can tell curl to
              select the user name and password from your environment  by
              specifying a single colon with this option: "-U :".

              On  systems where it works, curl will hide the given option
              argument from process listings. This is not enough to  pro‐
              tect  credentials from possibly getting seen by other users
              on the same system as they will  still  be  visible  for  a
              brief  moment before cleared. Such sensitive data should be
              retrieved from a file instead or similar and never used  in
              clear text in a command line.

              If  this option is used several times, the last one will be
              used.

       -x, --proxy [protocol://]host[:port]
              Use the specified proxy.

              The proxy string can be specified with a  protocol://  pre‐
              fix.  No  protocol  specified or http:// will be treated as
              HTTP  proxy.  Use  socks4://,  socks4a://,   socks5://   or
              socks5h://  to request a specific SOCKS version to be used.
              (The protocol support was added in curl 7.21.7)

              HTTPS proxy support via https:// protocol prefix was  added
              in 7.52.0 for OpenSSL, GnuTLS and NSS.

              Unrecognized and unsupported proxy protocols cause an error
              since 7.52.0.  Prior versions may ignore the  protocol  and
              use http:// instead.

              If the port number is not specified in the proxy string, it
              is assumed to be 1080.

              This option overrides existing environment  variables  that
              set  the  proxy  to use. If there's an environment variable
              setting a proxy, you can set proxy to "" to override it.

              All operations that are performed over an HTTP  proxy  will
              transparently  be  converted to HTTP. It means that certain
              protocol specific operations might not be  available.  This
              is not the case if you can tunnel through the proxy, as one
              with the -p, --proxytunnel option.

              User and password that  might  be  provided  in  the  proxy
              string  are URL decoded by curl. This allows you to pass in
              special characters such as @ by using  %40  or  pass  in  a
              colon with %3a.

              The  proxy  host can be specified the exact same way as the
              proxy environment variables, including the protocol  prefix
              (http://) and the embedded user + password.

              If  this option is used several times, the last one will be
              used.

       --proxy1.0 <host[:port]>
              Use the specified HTTP 1.0 proxy. If the port number is not
              specified, it is assumed at port 1080.

              The  only difference between this and the HTTP proxy option
              -x, --proxy, is that attempts to use  CONNECT  through  the
              proxy  will  specify  an  HTTP  1.0 protocol instead of the
              default HTTP 1.1.

       -p, --proxytunnel
              When an HTTP proxy is used -x, --proxy,  this  option  will
              make  curl tunnel through the proxy. The tunnel approach is
              made with the HTTP proxy CONNECT request and requires  that
              the  proxy  allows direct connect to the remote port number
              curl wants to tunnel through to.

              To suppress proxy CONNECT response headers when curl is set
              to output headers use --suppress-connect-headers.

              See also -x, --proxy.

       --pubkey <key>
              (SFTP SCP) Public key file name. Allows you to provide your
              public key in this separate file.

              If this option is used several times, the last one will  be
              used.

              (As  of  7.39.0, curl attempts to automatically extract the
              public key from the  private  key  file,  so  passing  this
              option is generally not required. Note that this public key
              extraction requires libcurl to be linked against a copy  of
              libssh2  1.2.8  or  higher  that  is  itself linked against
              OpenSSL.)

       -Q, --quote
              (FTP SFTP) Send an arbitrary command to the remote  FTP  or
              SFTP  server.  Quote  commands are sent BEFORE the transfer
              takes place (just after the initial PWD command in  an  FTP
              transfer, to be exact). To make commands take place after a
              successful transfer, prefix them with a dash '-'.  To  make
              commands  be sent after curl has changed the working direc‐
              tory, just before the transfer command(s), prefix the  com‐
              mand  with  a '+' (this is only supported for FTP). You may
              specify any number of commands.

              If the server returns failure for one of the commands,  the
              entire  operation  will be aborted. You must send syntacti‐
              cally correct FTP  commands  as  RFC  959  defines  to  FTP
              servers,  or  one  of  the  commands  listed  below to SFTP
              servers.

              Prefix the command with an asterisk (*) to make  curl  con‐
              tinue  even  if  the  command fails as by default curl will
              stop at first failure.

              This option can be used multiple times.

              SFTP is a binary protocol. Unlike for FTP, curl  interprets
              SFTP  quote  commands  itself  before  sending  them to the
              server.  File names may be quoted shell-style to embed spa‐
              ces  or  special  characters.  Following is the list of all
              supported SFTP quote commands:

              chgrp group file
                     The chgrp command sets the  group  ID  of  the  file
                     named  by the file operand to the group ID specified
                     by the group operand. The group operand is a decimal
                     integer group ID.

              chmod mode file
                     The chmod command modifies the file mode bits of the
                     specified file. The mode operand is an octal integer
                     mode number.

              chown user file
                     The  chown  command sets the owner of the file named
                     by the file operand to the user ID specified by  the
                     user  operand. The user operand is a decimal integer
                     user ID.

              ln source_file target_file
                     The ln and symlink commands create a  symbolic  link
                     at   the   target_file   location  pointing  to  the
                     source_file location.

              mkdir directory_name
                     The mkdir command creates the directory named by the
                     directory_name operand.

              pwd    The pwd command returns the absolute pathname of the
                     current working directory.

              rename source target
                     The rename command renames  the  file  or  directory
                     named  by the source operand to the destination path
                     named by the target operand.

              rm file
                     The rm command removes the  file  specified  by  the
                     file operand.

              rmdir directory
                     The rmdir command removes the directory entry speci‐
                     fied by the directory operand, provided it is empty.

              symlink source_file target_file
                     See ln.

       --random-file <file>
              Specify the path name to file containing what will be  con‐
              sidered  as  random  data. The data may be used to seed the
              random engine for SSL connections.  See also the --egd-file
              option.

       -r, --range <range>
              (HTTP  FTP SFTP FILE) Retrieve a byte range (i.e. a partial
              document) from an HTTP/1.1, FTP or SFTP server or  a  local
              FILE. Ranges can be specified in a number of ways.

              0-499     specifies the first 500 bytes

              500-999   specifies the second 500 bytes

              -500      specifies the last 500 bytes

              9500-     specifies the bytes from offset 9500 and forward

              0-0,-1    specifies the first and last byte only(*)(HTTP)

              100-199,500-599
                        specifies two separate 100-byte ranges(*) (HTTP)

              (*)  = NOTE that this will cause the server to reply with a
              multipart response!

              Only digit characters (0-9) are valid in  the  'start'  and
              'stop'  fields  of the 'start-stop' range syntax. If a non-
              digit  character  is  given  in  the  range,  the  server's
              response  will  be  unspecified,  depending on the server's
              configuration.

              You should also be aware that many HTTP/1.1 servers do  not
              have  this feature enabled, so that when you attempt to get
              a range, you'll instead get the whole document.

              FTP and  SFTP  range  downloads  only  support  the  simple
              'start-stop'  syntax  (optionally  with  one of the numbers
              omitted). FTP use depends on the extended FTP command SIZE.

              If this option is used several times, the last one will  be
              used.

       --raw  (HTTP) When used, it disables all internal HTTP decoding of
              content or transfer encodings and instead makes them passed
              on unaltered, raw.

              Added in 7.16.2.

       -e, --referer <URL>
              (HTTP)  Sends  the  "Referrer Page" information to the HTTP
              server. This can also be set with the -H, --header flag  of
              course.   When  used  with  -L,  --location  you can append
              ";auto" to the -e, --referer URL to make curl automatically
              set  the  previous  URL when it follows a Location: header.
              The ";auto" string can be used alone, even if you don't set
              an initial -e, --referer.

              If  this option is used several times, the last one will be
              used.

              See also -A, --user-agent and -H, --header.

       -J, --remote-header-name
              (HTTP) This option tells the -O,  --remote-name  option  to
              use   the   server-specified  Content-Disposition  filename
              instead of extracting a filename from the URL.

              If the server specifies a file name and a  file  with  that
              name  already  exists  in  the current working directory it
              will not be overwritten and an error  will  occur.  If  the
              server  doesn't specify a file name then this option has no
              effect.

              There's no attempt to decode %-sequences (yet) in the  pro‐
              vided file name, so this option may provide you with rather
              unexpected file names.

              WARNING: Exercise judicious use of this option,  especially
              on Windows. A rogue server could send you the name of a DLL
              or other file that could possibly be  loaded  automatically
              by Windows or some third party software.

       --remote-name-all
              This  option  changes the default action for all given URLs
              to be dealt with as if -O, --remote-name were used for each
              one.  So  if  you  want  to disable that for a specific URL
              after --remote-name-all has been used, you must use "-o  -"
              or --no-remote-name.

              Added in 7.19.0.

       -O, --remote-name
              Write  output to a local file named like the remote file we
              get. (Only the file part of the remote file  is  used,  the
              path is cut off.)

              The file will be saved in the current working directory. If
              you want the file saved in a different directory, make sure
              you  change  the  current working directory before invoking
              curl with this option.

              The remote file name to use for saving  is  extracted  from
              the  given  URL,  nothing else, and if it already exists it
              will be overwritten. If you want the server to be  able  to
              choose  the  file  name  refer  to -J, --remote-header-name
              which can be used in addition to this option. If the server
              chooses  a  file  name and that name already exists it will
              not be overwritten.

              There is no URL decoding done on the file name. If  it  has
              %20  or  other URL encoded parts of the name, they will end
              up as-is as file name.

              You may use this option as many times as the number of URLs
              you have.

       -R, --remote-time
              When  used,  this  will make curl attempt to figure out the
              timestamp of the remote file, and if that is available make
              the local file get that same timestamp.

       --request-target
              (HTTP)  Tells  curl  to  use an alternative "target" (path)
              instead of using the path as provided in the URL.  Particu‐
              larly  useful  when  wanting to issue HTTP requests without
              leading slash or other data that doesn't follow the regular
              URL pattern, like "OPTIONS *".

              Added in 7.55.0.

       -X, --request <command>
              (HTTP) Specifies a custom request method to use when commu‐
              nicating with  the  HTTP  server.   The  specified  request
              method  will  be  used instead of the method otherwise used
              (which defaults to GET). Read the  HTTP  1.1  specification
              for   details  and  explanations.  Common  additional  HTTP
              requests include PUT and DELETE, but  related  technologies
              like WebDAV offers PROPFIND, COPY, MOVE and more.

              Normally  you  don't  need  this  option. All sorts of GET,
              HEAD, POST and PUT requests are  rather  invoked  by  using
              dedicated command line options.

              This  option  only changes the actual word used in the HTTP
              request, it does not alter the way  curl  behaves.  So  for
              example if you want to make a proper HEAD request, using -X
              HEAD will not suffice. You  need  to  use  the  -I,  --head
              option.

              The  method  string you set with -X, --request will be used
              for all requests, which if you for example use -L,  --loca‐
              tion  may  cause  unintended side-effects when curl doesn't
              change request method according to the  HTTP  30x  response
              codes - and similar.

              (FTP) Specifies a custom FTP command to use instead of LIST
              when doing file lists with FTP.

              (POP3) Specifies a custom POP3 command to  use  instead  of
              LIST or RETR. (Added in 7.26.0)

              (IMAP)  Specifies  a  custom IMAP command to use instead of
              LIST. (Added in 7.30.0)

              (SMTP) Specifies a custom SMTP command to  use  instead  of
              HELP or VRFY. (Added in 7.34.0)

              If  this option is used several times, the last one will be
              used.

       --resolve <host:port:address[,address]...>
              Provide a custom address for a specific host and port pair.
              Using  this, you can make the curl requests(s) use a speci‐
              fied address and prevent the  otherwise  normally  resolved
              address to be used. Consider it a sort of /etc/hosts alter‐
              native provided on the command line. The port number should
              be  the number used for the specific protocol the host will
              be used for. It means you need several entries if you  want
              to provide address for the same host but different ports.

              By  specifying '*' as host you can tell curl to resolve any
              host and specific port pair to the specified address. Wild‐
              card is resolved last so any --resolve with a specific host
              and port will be used first.

              The provided address set by this option will be  used  even
              if -4, --ipv4 or -6, --ipv6 is set to make curl use another
              IP version.

              Support for providing the IP address within [brackets]  was
              added in 7.57.0.

              Support  for  providing multiple IP addresses per entry was
              added in 7.59.0.

              Support for resolving with wildcard was added in 7.64.0.

              This option can be used many times to add many  host  names
              to resolve.

              Added in 7.21.3.

       --retry-connrefused
              In  addition to the other conditions, consider ECONNREFUSED
              as a transient error too for --retry. This option  is  used
              together with --retry.

              Added in 7.52.0.

       --retry-delay <seconds>
              Make  curl sleep this amount of time before each retry when
              a transfer has failed with a transient  error  (it  changes
              the  default  backoff time algorithm between retries). This
              option is only interesting if --retry is also used. Setting
              this  delay  to zero will make curl use the default backoff
              time.

              If this option is used several times, the last one will  be
              used.

              Added in 7.12.3.

       --retry-max-time <seconds>
              The retry timer is reset before the first transfer attempt.
              Retries will be done as usual (see --retry) as long as  the
              timer  hasn't  reached this given limit. Notice that if the
              timer hasn't reached the limit, the request  will  be  made
              and  while  performing,  it may take longer than this given
              time period. To limit a single request´s maximum time,  use
              -m,  --max-time.   Set  this  option to zero to not timeout
              retries.

              If this option is used several times, the last one will  be
              used.

              Added in 7.12.3.

       --retry <num>
              If a transient error is returned when curl tries to perform
              a transfer, it will retry this number of times before  giv‐
              ing  up.  Setting  the number to 0 makes curl do no retries
              (which is the default). Transient  error  means  either:  a
              timeout,  an  FTP  4xx  response code or an HTTP 408 or 5xx
              response code.

              When curl is about to retry a transfer, it will first  wait
              one  second  and  then  for all forthcoming retries it will
              double the waiting time until it reaches 10  minutes  which
              then will be the delay between the rest of the retries.  By
              using --retry-delay you disable  this  exponential  backoff
              algorithm.  See  also  --retry-max-time  to limit the total
              time allowed for retries.

              Since curl 7.66.0, curl will comply with  the  Retry-After:
              response  header  if  one was present to know when to issue
              the next retry.

              If this option is used several times, the last one will  be
              used.

              Added in 7.12.3.

       --sasl-authzid
              Use  this  authorisation  identity  (authzid),  during SASL
              PLAIN authentication, in  addition  to  the  authentication
              identity (authcid) as specified by -u, --user.

              If  the  option isn't specified, the server will derive the
              authzid from the authcid, but if specified,  and  depending
              on  the  server  implementation,  it  may be used to access
              another user's inbox, that the user has been granted access
              to, or a shared mailbox for example.

              Added in 7.66.0.

       --sasl-ir
              Enable initial response in SASL authentication.

              Added in 7.31.0.

       --service-name <name>
              This  option  allows  you  to  change  the service name for
              SPNEGO.

              Examples:  --negotiate  --service-name  sockd   would   use
              sockd/server-name.

              Added in 7.43.0.

       -S, --show-error
              When  used  with  -s, --silent, it makes curl show an error
              message if it fails.

       -s, --silent
              Silent or quiet mode. Don't show progress  meter  or  error
              messages.   Makes  Curl mute. It will still output the data
              you ask for, potentially even to the terminal/stdout unless
              you redirect it.

              Use  -S, --show-error in addition to this option to disable
              progress meter but still show error messages.

              See also -v, --verbose and --stderr.

       --socks4 <host[:port]>
              Use the specified SOCKS4 proxy. If the port number  is  not
              specified, it is assumed at port 1080.

              This  option  overrides any previous use of -x, --proxy, as
              they are mutually exclusive.

              Since 7.21.7, this option  is  superfluous  since  you  can
              specify  a  socks4 proxy with -x, --proxy using a socks4://
              protocol prefix.

              Since 7.52.0, --preproxy can be used  to  specify  a  SOCKS
              proxy  at  the  same  time  -x,  --proxy  is  used  with an
              HTTP/HTTPS proxy. In such a case curl first connects to the
              SOCKS  proxy  and then connects (through SOCKS) to the HTTP
              or HTTPS proxy.

              If this option is used several times, the last one will  be
              used.

              Added in 7.15.2.

       --socks4a <host[:port]>
              Use  the specified SOCKS4a proxy. If the port number is not
              specified, it is assumed at port 1080.

              This option overrides any previous use of -x,  --proxy,  as
              they are mutually exclusive.

              Since  7.21.7,  this  option  is  superfluous since you can
              specify a socks4a proxy with -x, --proxy using a socks4a://
              protocol prefix.

              Since  7.52.0,  --preproxy  can  be used to specify a SOCKS
              proxy at  the  same  time  -x,  --proxy  is  used  with  an
              HTTP/HTTPS proxy. In such a case curl first connects to the
              SOCKS proxy and then connects (through SOCKS) to  the  HTTP
              or HTTPS proxy.

              If  this option is used several times, the last one will be
              used.

              Added in 7.18.0.

       --socks5-basic
              Tells curl to  use  username/password  authentication  when
              connecting   to  a  SOCKS5  proxy.   The  username/password
              authentication is enabled by default.  Use  --socks5-gssapi
              to force GSS-API authentication to SOCKS5 proxies.

              Added in 7.55.0.

       --socks5-gssapi-nec
              As  part  of  the  GSS-API negotiation a protection mode is
              negotiated. RFC 1961 says in section 4.3/4.4 it  should  be
              protected,  but  the NEC reference implementation does not.
              The  option  --socks5-gssapi-nec  allows  the   unprotected
              exchange of the protection mode negotiation.

              Added in 7.19.4.

       --socks5-gssapi-service <name>
              The default service name for a socks server is rcmd/server-
              fqdn. This option allows you to change it.

              Examples: --socks5 proxy-name --socks5-gssapi-service sockd
              would     use    sockd/proxy-name    --socks5    proxy-name
              --socks5-gssapi-service    sockd/real-name    would     use
              sockd/real-name  for  cases  where  the proxy-name does not
              match the principal name.

              Added in 7.19.4.

       --socks5-gssapi
              Tells curl to use GSS-API authentication when connecting to
              a  SOCKS5  proxy.  The GSS-API authentication is enabled by
              default (if curl is compiled with  GSS-API  support).   Use
              --socks5-basic to force username/password authentication to
              SOCKS5 proxies.

              Added in 7.55.0.

       --socks5-hostname <host[:port]>
              Use the specified SOCKS5 proxy (and let the  proxy  resolve
              the  host name). If the port number is not specified, it is
              assumed at port 1080.

              This option overrides any previous use of -x,  --proxy,  as
              they are mutually exclusive.

              Since  7.21.7,  this  option  is  superfluous since you can
              specify a socks5 hostname proxy with -x,  --proxy  using  a
              socks5h:// protocol prefix.

              Since  7.52.0,  --preproxy  can  be used to specify a SOCKS
              proxy at  the  same  time  -x,  --proxy  is  used  with  an
              HTTP/HTTPS proxy. In such a case curl first connects to the
              SOCKS proxy and then connects (through SOCKS) to  the  HTTP
              or HTTPS proxy.

              If  this option is used several times, the last one will be
              used.

              Added in 7.18.0.

       --socks5 <host[:port]>
              Use the specified SOCKS5 proxy - but resolve the host  name
              locally. If the port number is not specified, it is assumed
              at port 1080.

              This option overrides any previous use of -x,  --proxy,  as
              they are mutually exclusive.

              Since  7.21.7,  this  option  is  superfluous since you can
              specify a socks5 proxy with -x, --proxy using  a  socks5://
              protocol prefix.

              Since  7.52.0,  --preproxy  can  be used to specify a SOCKS
              proxy at  the  same  time  -x,  --proxy  is  used  with  an
              HTTP/HTTPS proxy. In such a case curl first connects to the
              SOCKS proxy and then connects (through SOCKS) to  the  HTTP
              or HTTPS proxy.

              If  this option is used several times, the last one will be
              used.

              This option (as well as --socks4) does not work with  IPV6,
              FTPS or LDAP.

              Added in 7.18.0.

       -Y, --speed-limit <speed>
              If a download is slower than this given speed (in bytes per
              second) for speed-time seconds it gets aborted.  speed-time
              is set with -y, --speed-time and is 30 if not set.

              If  this option is used several times, the last one will be
              used.

       -y, --speed-time <seconds>
              If a download is slower than speed-limit bytes  per  second
              during  a  speed-time period, the download gets aborted. If
              speed-time is used,  the  default  speed-limit  will  be  1
              unless set with -Y, --speed-limit.

              This  option  controls  transfers  and thus will not affect
              slow connects etc. If this is a concern for  you,  try  the
              --connect-timeout option.

              If  this option is used several times, the last one will be
              used.

       --ssl-allow-beast
              This option tells curl to not work around a  security  flaw
              in  the  SSL3 and TLS1.0 protocols known as BEAST.  If this
              option isn't used, the SSL layer may use workarounds  known
              to  cause  interoperability  problems  with  some older SSL
              implementations. WARNING: this option loosens the SSL secu‐
              rity, and by using this flag you ask for exactly that.

              Added in 7.25.0.

       --ssl-no-revoke
              (Schannel)  This  option  tells curl to disable certificate
              revocation checks.  WARNING: this option  loosens  the  SSL
              security, and by using this flag you ask for exactly that.

              Added in 7.44.0.

       --ssl-reqd
              (FTP  IMAP  POP3  SMTP) Require SSL/TLS for the connection.
              Terminates the connection if  the  server  doesn't  support
              SSL/TLS.

              This option was formerly known as --ftp-ssl-reqd.

              Added in 7.20.0.

       --ssl  (FTP IMAP POP3 SMTP) Try to use SSL/TLS for the connection.
              Reverts to a non-secure connection if  the  server  doesn't
              support SSL/TLS.  See also --ftp-ssl-control and --ssl-reqd
              for different levels of encryption required.

              This option was  formerly  known  as  --ftp-ssl  (Added  in
              7.11.0).  That  option  name  can still be used but will be
              removed in a future version.

              Added in 7.20.0.

       -2, --sslv2
              (SSL) Forces curl to use SSL  version  2  when  negotiating
              with  a  remote SSL server. Sometimes curl is built without
              SSLv2 support. SSLv2 is widely considered insecure (see RFC
              6176).

              See  also  --http1.1 and --http2. -2, --sslv2 requires that
              the underlying libcurl  was  built  to  support  TLS.  This
              option  overrides -3, --sslv3 and -1, --tlsv1 and --tlsv1.1
              and --tlsv1.2.

       -3, --sslv3
              (SSL) Forces curl to use SSL  version  3  when  negotiating
              with  a  remote SSL server. Sometimes curl is built without
              SSLv3 support. SSLv3 is widely considered insecure (see RFC
              7568).

              See  also  --http1.1 and --http2. -3, --sslv3 requires that
              the underlying libcurl  was  built  to  support  TLS.  This
              option  overrides -2, --sslv2 and -1, --tlsv1 and --tlsv1.1
              and --tlsv1.2.

       --stderr
              Redirect  all  writes  to  stderr  to  the  specified  file
              instead.  If  the  file  name is a plain '-', it is instead
              written to stdout.

              If this option is used several times, the last one will  be
              used.

              See also -v, --verbose and -s, --silent.

       --styled-output
              Enables  the automatic use of bold font styles when writing
              HTTP headers to the  terminal.  Use  --no-styled-output  to
              switch them off.

              Added in 7.61.0.

       --suppress-connect-headers
              When  -p,  --proxytunnel  is  used and a CONNECT request is
              made don't output  proxy  CONNECT  response  headers.  This
              option  is  meant  to be used with -D, --dump-header or -i,
              --include which are used to show protocol  headers  in  the
              output.  It  has  no  effect  on  debug options such as -v,
              --verbose or --trace, or any statistics.

              See also  -D,  --dump-header  and  -i,  --include  and  -p,
              --proxytunnel.

       --tcp-fastopen
              Enable use of TCP Fast Open (RFC7413).

              Added in 7.49.0.

       --tcp-nodelay
              Turn on the TCP_NODELAY option. See the curl_easy_setopt(3)
              man page for details about this option.

              Since 7.50.2, curl sets this option by default and you need
              to explicitly switch it off if you don't want it on.

              Added in 7.11.2.

       -t, --telnet-option <opt=val>
              Pass options to the telnet protocol. Supported options are:

              TTYPE=<term> Sets the terminal type.

              XDISPLOC=<X display> Sets the X display location.

              NEW_ENV=<var,val> Sets an environment variable.

       --tftp-blksize <value>
              (TFTP)  Set TFTP BLKSIZE option (must be >512). This is the
              block size that curl will try to use when transferring data
              to  or  from  a  TFTP  server. By default 512 bytes will be
              used.

              If this option is used several times, the last one will  be
              used.

              Added in 7.20.0.

       --tftp-no-options
              (TFTP) Tells curl not to send TFTP options requests.

              This  option improves interop with some legacy servers that
              do not acknowledge or properly implement TFTP options. When
              this option is used --tftp-blksize is ignored.

              Added in 7.48.0.

       -z, --time-cond <time>
              (HTTP FTP) Request a file that has been modified later than
              the given time and date, or  one  that  has  been  modified
              before that time. The <date expression> can be all sorts of
              date strings or if it doesn't match any internal  ones,  it
              is  taken  as  a filename and tries to get the modification
              date (mtime) from <file> instead. See  the  curl_getdate(3)
              man pages for date expression details.

              Start  the  date  expression  with  a  dash  (-) to make it
              request for  a  document  that  is  older  than  the  given
              date/time,  default  is  a  document that is newer than the
              specified date/time.

              If this option is used several times, the last one will  be
              used.

       --tls-max <VERSION>
              (SSL)  VERSION  defines  maximum supported TLS version. The
              minimum acceptable version  is  set  by  tlsv1.0,  tlsv1.1,
              tlsv1.2 or tlsv1.3.

              default
                     Use up to recommended TLS version.

              1.0    Use up to TLSv1.0.

              1.1    Use up to TLSv1.1.

              1.2    Use up to TLSv1.2.

              1.3    Use up to TLSv1.3.

       See  also  --tlsv1.0  and  --tlsv1.1  and --tlsv1.2 and --tlsv1.3.
       --tls-max requires that the underlying libcurl was built  to  sup‐
       port TLS. Added in 7.54.0.

       --tls13-ciphers <list of TLS 1.3 ciphersuites>
              (TLS)  Specifies  which cipher suites to use in the connec‐
              tion if it negotiates TLS 1.3. The list of  ciphers  suites
              must specify valid ciphers. Read up on TLS 1.3 cipher suite
              details on this URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              This option is currently used only when curl  is  built  to
              use  OpenSSL  1.1.1  or later. If you are using a different
              SSL backend you can try setting TLS 1.3  cipher  suites  by
              using the --ciphers option.

              If  this option is used several times, the last one will be
              used.

       --tlsauthtype <type>
              Set TLS authentication type. Currently, the only  supported
              option  is  "SRP", for TLS-SRP (RFC 5054). If --tlsuser and
              --tlspassword are specified but --tlsauthtype is not,  then
              this  option  defaults to "SRP".  This option works only if
              the underlying libcurl is built with TLS-SRP support, which
              requires OpenSSL or GnuTLS with TLS-SRP support.

              Added in 7.21.4.

       --tlspassword
              Set  password  for  use  with the TLS authentication method
              specified with --tlsauthtype. Requires that --tlsuser  also
              be set.

              This doesn't work with TLS 1.3.

              Added in 7.21.4.

       --tlsuser <name>
              Set  username  for  use  with the TLS authentication method
              specified with --tlsauthtype. Requires  that  --tlspassword
              also is set.

              This doesn't work with TLS 1.3.

              Added in 7.21.4.

       --tlsv1.0
              (TLS) Forces curl to use TLS version 1.0 or later when con‐
              necting to a remote TLS server.

              In old versions of curl this option was documented to allow
              _only_  TLS 1.0, but behavior was inconsistent depending on
              the TLS library. Use --tls-max if you want to set a maximum
              TLS version.

              Added in 7.34.0.

       --tlsv1.1
              (TLS) Forces curl to use TLS version 1.1 or later when con‐
              necting to a remote TLS server.

              In old versions of curl this option was documented to allow
              _only_  TLS 1.1, but behavior was inconsistent depending on
              the TLS library. Use --tls-max if you want to set a maximum
              TLS version.

              Added in 7.34.0.

       --tlsv1.2
              (TLS) Forces curl to use TLS version 1.2 or later when con‐
              necting to a remote TLS server.

              In old versions of curl this option was documented to allow
              _only_  TLS 1.2, but behavior was inconsistent depending on
              the TLS library. Use --tls-max if you want to set a maximum
              TLS version.

              Added in 7.34.0.

       --tlsv1.3
              (TLS) Forces curl to use TLS version 1.3 or later when con‐
              necting to a remote TLS server.

              Note that TLS 1.3 is only supported  by  a  subset  of  TLS
              backends.  At the time of this writing, they are BoringSSL,
              NSS, and Secure Transport (on iOS 11 or  later,  and  macOS
              10.13 or later).

              Added in 7.52.0.

       -1, --tlsv1
              (SSL) Tells curl to use at least TLS version 1.x when nego‐
              tiating with a remote TLS server. That  means  TLS  version
              1.0 or higher

              See  also  --http1.1 and --http2. -1, --tlsv1 requires that
              the underlying libcurl  was  built  to  support  TLS.  This
              option overrides --tlsv1.1 and --tlsv1.2 and --tlsv1.3.

       --tr-encoding
              (HTTP)  Request  a  compressed  Transfer-Encoding  response
              using one of the algorithms curl supports,  and  uncompress
              the data while receiving it.

              Added in 7.21.6.

       --trace-ascii <file>
              Enables  a  full  trace  dump  of all incoming and outgoing
              data, including descriptive information, to the given  out‐
              put  file.  Use  "-" as filename to have the output sent to
              stdout.

              This is very similar to --trace, but  leaves  out  the  hex
              part  and  only  shows the ASCII part of the dump. It makes
              smaller output that might be easier to read  for  untrained
              humans.

              If  this option is used several times, the last one will be
              used.

              This option overrides --trace and -v, --verbose.

       --trace-time
              Prepends a time stamp to each trace or  verbose  line  that
              curl displays.

              Added in 7.14.0.

       --trace <file>
              Enables  a  full  trace  dump  of all incoming and outgoing
              data, including descriptive information, to the given  out‐
              put  file.  Use  "-" as filename to have the output sent to
              stdout. Use "%" as filename to  have  the  output  sent  to
              stderr.

              If  this option is used several times, the last one will be
              used.

              This option overrides -v, --verbose and --trace-ascii.

       --unix-socket <path>
              (HTTP) Connect through this Unix domain socket, instead  of
              using the network.

              Added in 7.40.0.

       -T, --upload-file <file>
              This  transfers the specified local file to the remote URL.
              If there is no file part in the specified  URL,  curl  will
              append the local file name. NOTE that you must use a trail‐
              ing / on the last directory to really prove  to  Curl  that
              there  is  no  file  name or curl will think that your last
              directory name is the remote file name to  use.  That  will
              most  likely cause the upload operation to fail. If this is
              used on an HTTP(S) server, the PUT command will be used.

              Use the file name "-" (a single dash) to use stdin  instead
              of  a given file.  Alternately, the file name "." (a single
              period) may be specified instead of "-"  to  use  stdin  in
              non-blocking  mode  to  allow  reading  server output while
              stdin is being uploaded.

              You can specify one -T, --upload-file for each URL  on  the
              command  line.  Each -T, --upload-file + URL pair specifies
              what to upload and to where. curl also supports  "globbing"
              of  the  -T,  --upload-file  argument, meaning that you can
              upload multiple files to a single URL by using the same URL
              globbing style supported in the URL, like this:

               curl --upload-file "{file1,file2}" http://www.example.com

              or even

               curl -T "img[1-1000].png" ftp://ftp.example.com/upload/

              When  uploading  to  an  SMTP  server: the uploaded data is
              assumed to be RFC 5322 formatted. It  has  to  feature  the
              necessary  set of headers and mail body formatted correctly
              by the user as curl will not transcode nor encode  it  fur‐
              ther in any way.

       --url <url>
              Specify  a  URL  to fetch. This option is mostly handy when
              you want to specify URL(s) in a config file.

              If the  given  URL  is  missing  a  scheme  name  (such  as
              "http://"  or  "ftp://"  etc)  then  curl will make a guess
              based on the host. If the outermost sub-domain name matches
              DICT, FTP, IMAP, LDAP, POP3 or SMTP then that protocol will
              be used, otherwise HTTP will be used. Since 7.45.0 guessing
              can be disabled by setting a default protocol, see --proto-
              default for details.

              This option may be used any number  of  times.  To  control
              where  this URL is written, use the -o, --output or the -O,
              --remote-name options.

       -B, --use-ascii
              (FTP LDAP) Enable ASCII transfer. For FTP, this can also be
              enforced  by  using  a  URL  that ends with ";type=A". This
              option causes data sent to stdout to be in  text  mode  for
              win32 systems.

       -A, --user-agent <name>
              (HTTP)  Specify  the  User-Agent string to send to the HTTP
              server. To encode blanks in the string, surround the string
              with  single  quote marks. This header can also be set with
              the -H, --header or the --proxy-header options.

              If this option is used several times, the last one will  be
              used.

       -u, --user <user:password>
              Specify  the  user  name  and  password  to  use for server
              authentication. Overrides -n, --netrc and --netrc-optional.

              If you simply specify the user name, curl will prompt for a
              password.

              The  user  name  and  passwords  are  split up on the first
              colon, which makes it impossible to use a colon in the user
              name with this option. The password can, still.

              On  systems where it works, curl will hide the given option
              argument from process listings. This is not enough to  pro‐
              tect  credentials from possibly getting seen by other users
              on the same system as they will  still  be  visible  for  a
              brief  moment before cleared. Such sensitive data should be
              retrieved from a file instead or similar and never used  in
              clear text in a command line.

              When  using  Kerberos  V5  with  a Windows based server you
              should include the Windows domain name in the user name, in
              order  for  the  server  to  successfully obtain a Kerberos
              Ticket. If you don't then the initial authentication  hand‐
              shake may fail.

              When  using  NTLM, the user name can be specified simply as
              the user name, without the domain, if  there  is  a  single
              domain and forest in your setup for example.

              To specify the domain name use either Down-Level Logon Name
              or UPN (User Principal Name) formats.  For  example,  EXAM‐
              PLE\user and user@example.com respectively.

              If  you  use a Windows SSPI-enabled curl binary and perform
              Kerberos V5, Negotiate, NTLM or Digest authentication  then
              you can tell curl to select the user name and password from
              your environment by specifying a  single  colon  with  this
              option: "-u :".

              If  this option is used several times, the last one will be
              used.

       -v, --verbose
              Makes curl verbose during the operation. Useful for  debug‐
              ging  and  seeing  what's going on "under the hood". A line
              starting with '>' means "header data"  sent  by  curl,  '<'
              means "header data" received by curl that is hidden in nor‐
              mal cases, and a line starting with  '*'  means  additional
              info provided by curl.

              If  you only want HTTP headers in the output, -i, --include
              might be the option you're looking for.

              If you think this option  still  doesn't  give  you  enough
              details, consider using --trace or --trace-ascii instead.

              Use -s, --silent to make curl really quiet.

              See  also  -i, --include. This option overrides --trace and
              --trace-ascii.

       -V, --version
              Displays information about curl and the libcurl version  it
              uses.

              The  first  line includes the full version of curl, libcurl
              and other 3rd party libraries linked with the executable.

              The second line (starts with "Protocols:") shows all proto‐
              cols that libcurl reports to support.

              The  third  line  (starts  with "Features:") shows specific
              features  libcurl  reports  to  offer.  Available  features
              include:

              IPv6   You can use IPv6 with this.

              krb4   Krb4 for FTP is supported.

              SSL    SSL  versions  of  various  protocols are supported,
                     such as HTTPS, FTPS, POP3S and so on.

              libz   Automatic decompression  of  compressed  files  over
                     HTTP is supported.

              NTLM   NTLM authentication is supported.

              Debug  This  curl  uses  a  libcurl  built with Debug. This
                     enables more  error-tracking  and  memory  debugging
                     etc. For curl-developers only!

              AsynchDNS
                     This curl uses asynchronous name resolves. Asynchro‐
                     nous name resolves can be done using either  the  c-
                     ares or the threaded resolver backends.

              SPNEGO SPNEGO authentication is supported.

              Largefile
                     This  curl  supports transfers of large files, files
                     larger than 2GB.

              IDN    This curl supports IDN - international domain names.

              GSS-API
                     GSS-API is supported.

              SSPI   SSPI is supported.

              TLS-SRP
                     SRP (Secure Remote Password) authentication is  sup‐
                     ported for TLS.

              HTTP2  HTTP/2 support has been built-in.

              UnixSockets
                     Unix sockets support is provided.

              HTTPS-proxy
                     This curl is built to support HTTPS proxy.

              Metalink
                     This  curl  supports  Metalink (both version 3 and 4
                     (RFC 5854)), which  describes  mirrors  and  hashes.
                     curl  will  use  mirrors  for  failover if there are
                     errors (such as the file or server not being  avail‐
                     able).

              PSL    PSL  is  short for Public Suffix List and means that
                     this curl has been built with knowledge about  "pub‐
                     lic suffixes".

              MultiSSL
                     This curl supports multiple TLS backends.

       -w, --write-out <format>
              Make  curl  display information on stdout after a completed
              transfer. The format is a string  that  may  contain  plain
              text  mixed with any number of variables. The format can be
              specified as a literal "string", or you can have curl  read
              the format from a file with "@filename" and to tell curl to
              read the format from stdin you write "@-".

              The variables present in the output format will be  substi‐
              tuted  by  the  value  or  text  that  curl  thinks fit, as
              described below. All variables  are  specified  as  %{vari‐
              able_name}  and to output a normal % you just write them as
              %%. You can output a newline by using \n, a carriage return
              with \r and a tab space with \t.

              The output will be written to standard output, but this can
              be switched to standard error by using %{stderr}.

              NOTE: The %-symbol is a special symbol in  the  win32-envi‐
              ronment,  where  all  occurrences of % must be doubled when
              using this option.

              The variables available are:

              content_type   The Content-Type of the requested  document,
                             if there was any.

              filename_effective
                             The  ultimate  filename that curl writes out
                             to. This is only meaningful if curl is  told
                             to  write  to  a file with the -O, --remote-
                             name or -o, --output option. It's most  use‐
                             ful  in  combination  with the -J, --remote-
                             header-name option. (Added in 7.26.0)

              ftp_entry_path The initial path curl ended up in when  log‐
                             ging  on to the remote FTP server. (Added in
                             7.15.4)

              http_code      The numerical response code that  was  found
                             in  the  last  retrieved  HTTP(S)  or FTP(s)
                             transfer. In 7.18.2 the alias  response_code
                             was added to show the same info.

              http_connect   The  numerical  code  that  was found in the
                             last response (from a proxy) to a curl  CON‐
                             NECT request. (Added in 7.12.4)

              http_version   The  http version that was effectively used.
                             (Added in 7.50.0)

              local_ip       The IP address of the local end of the  most
                             recently  done  connection  -  can be either
                             IPv4 or IPv6 (Added in 7.29.0)

              local_port     The local port number of the  most  recently
                             done connection (Added in 7.29.0)

              num_connects   Number  of  new  connects made in the recent
                             transfer. (Added in 7.12.3)

              num_redirects  Number of redirects that  were  followed  in
                             the request. (Added in 7.12.3)

              proxy_ssl_verify_result
                             The  result  of  the  HTTPS proxy's SSL peer
                             certificate verification that was requested.
                             0  means  the  verification  was successful.
                             (Added in 7.52.0)

              redirect_url   When an HTTP request was  made  without  -L,
                             --location  to  follow  redirects  (or  when
                             --max-redir is met), this variable will show
                             the  actual  URL  a redirect would have gone
                             to. (Added in 7.18.2)

              remote_ip      The remote IP address of the  most  recently
                             done connection - can be either IPv4 or IPv6
                             (Added in 7.29.0)

              remote_port    The remote port number of the most  recently
                             done connection (Added in 7.29.0)

              scheme         The  URL  scheme (sometimes called protocol)
                             that was effectively used (Added in 7.52.0)

              size_download  The total amount of bytes  that  were  down‐
                             loaded.

              size_header    The  total amount of bytes of the downloaded
                             headers.

              size_request   The total amount of bytes that were sent  in
                             the HTTP request.

              size_upload    The   total   amount   of  bytes  that  were
                             uploaded.

              speed_download The average download speed  that  curl  mea‐
                             sured  for  the complete download. Bytes per
                             second.

              speed_upload   The average upload speed that curl  measured
                             for the complete upload. Bytes per second.

              ssl_verify_result
                             The result of the SSL peer certificate veri‐
                             fication that was  requested.  0  means  the
                             verification   was   successful.  (Added  in
                             7.19.0)

              stderr         From this point on, the -w, --write-out out‐
                             put  will  be  written  to  standard  error.
                             (Added in 7.63.0)

              stdout         From this point on, the -w, --write-out out‐
                             put  will  be  written  to  standard output.
                             This is the default,  but  can  be  used  to
                             switch   back  after  switching  to  stderr.
                             (Added in 7.63.0)

              time_appconnect
                             The time, in seconds, it took from the start
                             until  the  SSL/SSH/etc connect/handshake to
                             the remote host  was  completed.  (Added  in
                             7.19.0)

              time_connect   The time, in seconds, it took from the start
                             until the TCP connect to the remote host (or
                             proxy) was completed.

              time_namelookup
                             The time, in seconds, it took from the start
                             until the name resolving was completed.

              time_pretransfer
                             The time, in seconds, it took from the start
                             until  the  file  transfer was just about to
                             begin. This includes all  pre-transfer  com‐
                             mands  and negotiations that are specific to
                             the particular protocol(s) involved.

              time_redirect  The time, in seconds, it took for all  redi‐
                             rection  steps  including  name lookup, con‐
                             nect, pretransfer and  transfer  before  the
                             final transaction was started. time_redirect
                             shows the complete execution time for multi‐
                             ple redirections. (Added in 7.12.3)

              time_starttransfer
                             The time, in seconds, it took from the start
                             until the first byte was just  about  to  be
                             transferred.  This includes time_pretransfer
                             and also the time the server needed to  cal‐
                             culate the result.

              time_total     The  total  time,  in seconds, that the full
                             operation lasted.

              url_effective  The URL that was fetched last. This is  most
                             meaningful  if  you've  told  curl to follow
                             location: headers.

              If this option is used several times, the last one will  be
              used.

       --xattr
              When  saving  output  to  a file, this option tells curl to
              store certain file metadata in  extended  file  attributes.
              Currently,   the   URL  is  stored  in  the  xdg.origin.url
              attribute and, for HTTP, the content type is stored in  the
              mime_type  attribute.  If  the file system does not support
              extended attributes, a warning is issued.

FILES
       ~/.curlrc
              Default config file, see -K, --config for details.

ENVIRONMENT
       The environment variables can be specified in lower case or  upper
       case.  The  lower  case  version  has precedence. http_proxy is an
       exception as it is only available in lower case.

       Using an environment variable to set the proxy has the same effect
       as using the -x, --proxy option.

       http_proxy [protocol://]<host>[:port]
              Sets the proxy server to use for HTTP.

       HTTPS_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for HTTPS.

       [url-protocol]_PROXY [protocol://]<host>[:port]
              Sets  the proxy server to use for [url-protocol], where the
              protocol is a protocol that curl supports and as  specified
              in a URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP etc.

       ALL_PROXY [protocol://]<host>[:port]
              Sets  the proxy server to use if no protocol-specific proxy
              is set.

       NO_PROXY <comma-separated list of hosts/domains>
              list of host names that shouldn't go through any proxy.  If
              set  to  an  asterisk  '*' only, it matches all hosts. Each
              name in this list is matched as either a domain name  which
              contains the hostname, or the hostname itself.

              This  environment  variable  disables use of the proxy even
              when  specified  with  the  -x,  --proxy  option.  That  is
              NO_PROXY=direct.example.com   curl   -x  http://proxy.exam‐
              ple.com http://direct.example.com accesses the  target  URL
              directly,    and    NO_PROXY=direct.example.com   curl   -x
              http://proxy.example.com       http://somewhere.example.com
              accesses the target URL through the proxy.

              The  list  of  host  names can also be include numerical IP
              addresses, and IPv6 versions should then be  given  without
              enclosing brackets.

PROXY PROTOCOL PREFIXES
       Since  curl version 7.21.7, the proxy string may be specified with
       a protocol:// prefix to specify alternative proxy protocols.

       If no protocol is specified in the proxy string or if  the  string
       doesn't  match  a  supported  one, the proxy will be treated as an
       HTTP proxy.

       The supported proxy protocol prefixes are as follows:

       http://
              Makes it use it as an HTTP proxy. The default if no  scheme
              prefix is used.

       https://
              Makes it treated as an HTTPS proxy.

       socks4://
              Makes it the equivalent of --socks4

       socks4a://
              Makes it the equivalent of --socks4a

       socks5://
              Makes it the equivalent of --socks5

       socks5h://
              Makes it the equivalent of --socks5-hostname

EXIT CODES
       There are a bunch of different error codes and their corresponding
       error messages that may appear during bad conditions. At the  time
       of this writing, the exit codes are:

       1      Unsupported protocol. This build of curl has no support for
              this protocol.

       2      Failed to initialize.

       3      URL malformed. The syntax was not correct.

       4      A feature or option that was needed to perform the  desired
              request  was  not  enabled  or  was  explicitly disabled at
              build-time. To make curl able to do this, you probably need
              another build of libcurl!

       5      Couldn't  resolve  proxy. The given proxy host could not be
              resolved.

       6      Couldn't resolve  host.  The  given  remote  host  was  not
              resolved.

       7      Failed to connect to host.

       8      Weird  server  reply.  The  server  sent data curl couldn't
              parse.

       9      FTP access denied. The server denied login or denied access
              to  the  particular  resource  or  directory  you wanted to
              reach. Most often you tried to change to a  directory  that
              doesn't exist on the server.

       10     FTP  accept failed. While waiting for the server to connect
              back when an active FTP session is used, an error code  was
              sent over the control connection or similar.

       11     FTP weird PASS reply. Curl couldn't parse the reply sent to
              the PASS request.

       12     During an active FTP session while waiting for  the  server
              to connect back to curl, the timeout expired.

       13     FTP weird PASV reply, Curl couldn't parse the reply sent to
              the PASV request.

       14     FTP weird 227 format. Curl couldn't parse the 227-line  the
              server sent.

       15     FTP  can't get host. Couldn't resolve the host IP we got in
              the 227-line.

       16     HTTP/2 error. A problem was detected in the  HTTP2  framing
              layer.  This is somewhat generic and can be one out of sev‐
              eral problems, see the error message for details.

       17     FTP couldn't set binary. Couldn't change transfer method to
              binary.

       18     Partial file. Only a part of the file was transferred.

       19     FTP  couldn't  download/access the given file, the RETR (or
              similar) command failed.

       21     FTP quote error. A quote command returned  error  from  the
              server.

       22     HTTP page not retrieved. The requested url was not found or
              returned another error with the HTTP error code  being  400
              or  above.  This  return code only appears if -f, --fail is
              used.

       23     Write error. Curl couldn't write data to a local filesystem
              or similar.

       25     FTP  couldn't  STOR file. The server denied the STOR opera‐
              tion, used for FTP uploading.

       26     Read error. Various reading problems.

       27     Out of memory. A memory allocation request failed.

       28     Operation  timeout.  The  specified  time-out  period   was
              reached according to the conditions.

       30     FTP  PORT  failed.  The  PORT  command  failed. Not all FTP
              servers support the PORT  command,  try  doing  a  transfer
              using PASV instead!

       31     FTP  couldn't  use REST. The REST command failed. This com‐
              mand is used for resumed FTP transfers.

       33     HTTP range error. The range "command" didn't work.

       34     HTTP post error. Internal post-request generation error.

       35     SSL connect error. The SSL handshaking failed.

       36     Bad download resume. Couldn't continue an  earlier  aborted
              download.

       37     FILE  couldn't  read file. Failed to open the file. Permis‐
              sions?

       38     LDAP cannot bind. LDAP bind operation failed.

       39     LDAP search failed.

       41     Function not found. A required LDAP function was not found.

       42     Aborted by callback. An application told curl to abort  the
              operation.

       43     Internal error. A function was called with a bad parameter.

       45     Interface  error.  A specified outgoing interface could not
              be used.

       47     Too many redirects. When following redirects, curl hit  the
              maximum amount.

       48     Unknown  option  specified  to libcurl. This indicates that
              you passed a weird option to curl that  was  passed  on  to
              libcurl and rejected. Read up in the manual!

       49     Malformed telnet option.

       51     The  peer's  SSL certificate or SSH MD5 fingerprint was not
              OK.

       52     The server didn't reply anything, which here is  considered
              an error.

       53     SSL crypto engine not found.

       54     Cannot set SSL crypto engine as default.

       55     Failed sending network data.

       56     Failure in receiving network data.

       58     Problem with the local certificate.

       59     Couldn't use specified SSL cipher.

       60     Peer certificate cannot be authenticated with known CA cer‐
              tificates.

       61     Unrecognized transfer encoding.

       62     Invalid LDAP URL.

       63     Maximum file size exceeded.

       64     Requested FTP SSL level failed.

       65     Sending the data requires a rewind that failed.

       66     Failed to initialise SSL Engine.

       67     The user name, password, or similar was  not  accepted  and
              curl failed to log in.

       68     File not found on TFTP server.

       69     Permission problem on TFTP server.

       70     Out of disk space on TFTP server.

       71     Illegal TFTP operation.

       72     Unknown TFTP transfer ID.

       73     File already exists (TFTP).

       74     No such user (TFTP).

       75     Character conversion failed.

       76     Character conversion functions required.

       77     Problem   with  reading  the  SSL  CA  cert  (path?  access
              rights?).

       78     The resource referenced in the URL does not exist.

       79     An unspecified error occurred during the SSH session.

       80     Failed to shut down the SSL connection.

       82     Could not load CRL file, missing or wrong format (added  in
              7.19.0).

       83     Issuer check failed (added in 7.19.0).

       84     The FTP PRET command failed

       85     RTSP: mismatch of CSeq numbers

       86     RTSP: mismatch of Session Identifiers

       87     unable to parse FTP file list

       88     FTP chunk callback reported error

       89     No connection available, the session will be queued

       90     SSL public key does not matched pinned public key

       91     Invalid SSL certificate status.

       92     Stream error in HTTP/2 framing layer.

       XX     More  error  codes will appear here in future releases. The
              existing ones are meant to never change.

AUTHORS / CONTRIBUTORS
       Daniel Stenberg is the main author, but the whole list of contrib‐
       utors is found in the separate THANKS file.

WWW
       https://curl.haxx.se

SEE ALSO
       ftp(1), wget(1)

Curl 7.69.1                 November 16, 2016                     curl(1)