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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)