MAN(1)                        Manual pager utils                        MAN(1)



NAME
       man - an interface to the on-line reference manuals

SYNOPSIS
       man  [-C  file]  [-d]  [-D]  [--warnings[=warnings]]  [-R encoding] [-L
       locale] [-m system[,...]] [-M path] [-S list]  [-e  extension]  [-i|-I]
       [--regex|--wildcard]   [--names-only]  [-a]  [-u]  [--no-subpages]  [-P
       pager] [-r prompt] [-7] [-E encoding] [--no-hyphenation] [--no-justifi‐
       cation]  [-p  string]  [-t]  [-T[device]]  [-H[browser]] [-X[dpi]] [-Z]
       [[section] page ...] ...
       man -k [apropos options] regexp ...
       man -K [-w|-W] [-S list] [-i|-I] [--regex] [section] term ...
       man -f [whatis options] page ...
       man -l [-C file] [-d] [-D] [--warnings[=warnings]]  [-R  encoding]  [-L
       locale]  [-P  pager]  [-r  prompt]  [-7] [-E encoding] [-p string] [-t]
       [-T[device]] [-H[browser]] [-X[dpi]] [-Z] file ...
       man -w|-W [-C file] [-d] [-D] page ...
       man -c [-C file] [-d] [-D] page ...
       man [-hV]

DESCRIPTION
       man is the system's manual pager. Each page argument given  to  man  is
       normally  the  name of a program, utility or function.  The manual page
       associated with each of these arguments is then found and displayed.  A
       section,  if  provided, will direct man to look only in that section of
       the manual.  The default action is to search in all  of  the  available
       sections, following a pre-defined order and to show only the first page
       found, even if page exists in several sections.

       The table below shows the section numbers of the manual followed by the
       types of pages they contain.


       1   Executable programs or shell commands
       2   System calls (functions provided by the kernel)
       3   Library calls (functions within program libraries)
       4   Special files (usually found in /dev)
       5   File formats and conventions eg /etc/passwd
       6   Games
       7   Miscellaneous  (including  macro  packages and conven‐
           tions), e.g. man(7), groff(7)
       8   System administration commands (usually only for root)
       9   Kernel routines [Non standard]

       A manual page consists of several sections.

       Conventional  section  names  include  NAME,  SYNOPSIS,  CONFIGURATION,
       DESCRIPTION,  OPTIONS,  EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT,
       FILES, VERSIONS, CONFORMING TO,  NOTES,  BUGS,  EXAMPLE,  AUTHORS,  and
       SEE ALSO.

       The following conventions apply to the SYNOPSIS section and can be used
       as a guide in other sections.


       bold text          type exactly as shown.
       italic text        replace with appropriate argument.
       [-abc]             any or all arguments within [ ] are optional.
       -a|-b              options delimited by | cannot be used together.
       argument ...       argument is repeatable.
       [expression] ...   entire expression within [ ] is repeatable.

       Exact rendering may vary depending on the output device.  For instance,
       man will usually not be able to render italics when running in a termi‐
       nal, and will typically use underlined or coloured text instead.

       The command or function illustration is a pattern that should match all
       possible invocations.  In some cases it is advisable to illustrate sev‐
       eral exclusive invocations as is shown in the SYNOPSIS section of  this
       manual page.

EXAMPLES
       man ls
           Display the manual page for the item (program) ls.

       man -a intro
           Display,  in  succession,  all  of the available intro manual pages
           contained within the manual.  It is possible to quit  between  suc‐
           cessive displays or skip any of them.

       man -t alias | lpr -Pps
           Format  the manual page referenced by `alias', usually a shell man‐
           ual page, into the default troff or groff format and pipe it to the
           printer  named  ps.   The default output for groff is usually Post‐
           Script.  man --help should advise as to which processor is bound to
           the -t option.

       man -l -Tdvi ./foo.1x.gz > ./foo.1x.dvi
           This  command  will  decompress  and format the nroff source manual
           page ./foo.1x.gz into a device independent (dvi) file.   The  redi‐
           rection is necessary as the -T flag causes output to be directed to
           stdout with no pager.  The output could be viewed  with  a  program
           such  as  xdvi or further processed into PostScript using a program
           such as dvips.

       man -k printf
           Search the short descriptions and manual page names for the keyword
           printf  as  regular expression.  Print out any matches.  Equivalent
           to apropos -r printf.

       man -f smail
           Lookup the manual pages referenced by smail and print out the short
           descriptions of any found.  Equivalent to whatis -r smail.

OVERVIEW
       Many  options are available to man in order to give as much flexibility
       as possible to the user.  Changes can be made to the search path,  sec‐
       tion  order,  output  processor,  and  other  behaviours and operations
       detailed below.

       If set, various environment variables are interrogated to determine the
       operation  of  man.   It  is  possible  to set the `catch all' variable
       $MANOPT to any string in command line format with  the  exception  that
       any  spaces  used as part of an option's argument must be escaped (pre‐
       ceded by a backslash).  man will parse $MANOPT prior to parsing its own
       command  line.   Those options requiring an argument will be overridden
       by the same options found on the command line.  To  reset  all  of  the
       options set in $MANOPT, -D can be specified as the initial command line
       option.  This will allow man to `forget' about the options specified in
       $MANOPT although they must still have been valid.

       The  manual  pager  utilities  packaged as man-db make extensive use of
       index database caches.  These caches contain information such as  where
       each  manual  page  can  be found on the filesystem and what its whatis
       (short one line description of the man page) contains, and allow man to
       run  faster  than  if it had to search the filesystem each time to find
       the appropriate manual page.  If requested using  the  -u  option,  man
       will  ensure  that  the caches remain consistent, which can obviate the
       need to manually run software to update traditional whatis  text  data‐
       bases.

       If  man  cannot  find a mandb initiated index database for a particular
       manual page hierarchy, it will still search for  the  requested  manual
       pages,  although  file globbing will be necessary to search within that
       hierarchy.  If whatis or apropos fails to find an index it will try  to
       extract information from a traditional whatis database instead.

       These  utilities  support  compressed  source  nroff  files  having, by
       default, the extensions of .Z, .z and .gz.  It is possible to deal with
       any  compression  extension, but this information must be known at com‐
       pile time.  Also, by default, any cat  pages  produced  are  compressed
       using gzip.  Each `global' manual page hierarchy such as /usr/share/man
       or /usr/X11R6/man may have any directory as  its  cat  page  hierarchy.
       Traditionally  the cat pages are stored under the same hierarchy as the
       man pages, but for reasons such as those specified in the File  Hierar‐
       chy  Standard  (FHS),  it  may  be better to store them elsewhere.  For
       details on how to do this, please read manpath(5).  For details on  why
       to do this, read the standard.

       International  support is available with this package.  Native language
       manual pages are accessible (if available on your system)  via  use  of
       locale  functions.   To  activate  such support, it is necessary to set
       either $LC_MESSAGES, $LANG  or  another  system  dependent  environment
       variable to your language locale, usually specified in the POSIX 1003.1
       based format:

       [_[.[,]]]

       If the desired page is available in your locale, it will  be  displayed
       in lieu of the standard (usually American English) page.

       Support  for  international message catalogues is also featured in this
       package and can be activated in the same way, again if  available.   If
       you  find  that  the  manual pages and message catalogues supplied with
       this package are not available in your native language  and  you  would
       like  to supply them, please contact the maintainer who will be coordi‐
       nating such activity.

       For information regarding other features and extensions available  with
       this manual pager, please read the documents supplied with the package.

DEFAULTS
       man  will search for the desired manual pages within the index database
       caches. If the -u option is given, a cache consistency  check  is  per‐
       formed  to  ensure the databases accurately reflect the filesystem.  If
       this option is always given, it is not generally necessary to run mandb
       after the caches are initially created, unless a cache becomes corrupt.
       However, the cache consistency check can be slow on systems  with  many
       manual  pages  installed, so it is not performed by default, and system
       administrators may wish to run mandb every week or so to keep the data‐
       base  caches  fresh.   To forestall problems caused by outdated caches,
       man will fall back to file globbing if a cache lookup fails, just as it
       would if no cache was present.

       Once  a  manual page has been located, a check is performed to find out
       if a relative preformatted `cat' file already exists and is newer  than
       the nroff file.  If it does and is, this preformatted file is (usually)
       decompressed and then displayed, via use of a pager.  The pager can  be
       specified  in  a number of ways, or else will fall back to a default is
       used (see option -P for details).  If no cat is found or is older  than
       the  nroff  file, the nroff is filtered through various programs and is
       shown immediately.

       If a cat file can be produced (a relative cat directory exists and  has
       appropriate  permissions),  man will compress and store the cat file in
       the background.

       The filters are deciphered by a number of means. Firstly,  the  command
       line option -p or the environment variable $MANROFFSEQ is interrogated.
       If -p was not used and the environment variable was not set,  the  ini‐
       tial  line  of  the nroff file is parsed for a preprocessor string.  To
       contain a valid preprocessor string, the first line must resemble

       '\" 

       where string can be any combination of letters described by  option  -p
       below.

       If  none of the above methods provide any filter information, a default
       set is used.

       A formatting pipeline is formed from the filters and the  primary  for‐
       matter  (nroff or [tg]roff with -t) and executed.  Alternatively, if an
       executable program mandb_nfmt (or mandb_tfmt with -t) exists in the man
       tree  root,  it  is executed instead.  It gets passed the manual source
       file, the preprocessor string, and optionally the device specified with
       -T or -E as arguments.

OPTIONS
       Non argument options that are duplicated either on the command line, in
       $MANOPT, or both, are not harmful.  For options that require  an  argu‐
       ment, each duplication will override the previous argument value.

   General options
       -C file, --config-file=file
              Use  this  user  configuration  file  rather than the default of
              ~/.manpath.

       -d, --debug
              Print debugging information.

       -D, --default
              This option is normally issued as  the  very  first  option  and
              resets  man's  behaviour  to  its  default.  Its use is to reset
              those options that may have been set in  $MANOPT.   Any  options
              that follow -D will have their usual effect.

       --warnings[=warnings]
              Enable  warnings from groff.  This may be used to perform sanity
              checks on the source text of manual pages.  warnings is a comma-
              separated  list  of  warning  names;  if it is not supplied, the
              default is "mac".  See the “Warnings” node in info groff  for  a
              list of available warning names.

   Main modes of operation
       -f, --whatis
              Equivalent to whatis.  Display a short description from the man‐
              ual page, if available. See whatis(1) for details.

       -k, --apropos
              Equivalent to apropos.  Search the short  manual  page  descrip‐
              tions  for keywords and display any matches.  See apropos(1) for
              details.

       -K, --global-apropos
              Search for text in all manual  pages.   This  is  a  brute-force
              search,  and is likely to take some time; if you can, you should
              specify a section to reduce the number of pages that need to  be
              searched.   Search terms may be simple strings (the default), or
              regular expressions if the --regex option is used.

       -l, --local-file
              Activate `local' mode.  Format and display  local  manual  files
              instead  of  searching  through  the system's manual collection.
              Each manual page argument will be interpreted as an nroff source
              file in the correct format.  No cat file is produced.  If '-' is
              listed as one of the arguments, input will be taken from  stdin.
              When  this  option  is  not used, and man fails to find the page
              required, before displaying the error message,  it  attempts  to
              act as if this option was supplied, using the name as a filename
              and looking for an exact match.

       -w, --where, --location
              Don't actually display the manual pages, but do print the  loca‐
              tion(s) of the source nroff files that would be formatted.

       -W, --where-cat, --location-cat
              Don't  actually display the manual pages, but do print the loca‐
              tion(s) of the cat files that would be displayed.  If -w and  -W
              are both specified, print both separated by a space.

       -c, --catman
              This  option  is  not for general use and should only be used by
              the catman program.

       -R encoding, --recode=encoding
              Instead of formatting the manual page in the usual  way,  output
              its  source converted to the specified encoding.  If you already
              know the encoding of the source file,  you  can  also  use  man‐
              conv(1)  directly.   However,  this option allows you to convert
              several manual pages to a  single  encoding  without  having  to
              explicitly  state  the encoding of each, provided that they were
              already installed in a structure similar to a manual page  hier‐
              archy.

   Finding manual pages
       -L locale, --locale=locale
              man will normally determine your current locale by a call to the
              C function setlocale(3) which interrogates  various  environment
              variables, possibly including $LC_MESSAGES and $LANG.  To tempo‐
              rarily override the determined value, use this option to  supply
              a  locale  string  directly  to man.  Note that it will not take
              effect until the search for pages actually begins.  Output  such
              as  the  help  message will always be displayed in the initially
              determined locale.

       -m system[,...], --systems=system[,...]
              If this system has access to  other  operating  system's  manual
              pages,  they can be accessed using this option.  To search for a
              manual page from NewOS's manual page collection, use the  option
              -m NewOS.

              The  system  specified  can  be a combination of comma delimited
              operating system names.  To include a search of the native oper‐
              ating  system's manual pages, include the system name man in the
              argument string.  This option will override the $SYSTEM environ‐
              ment variable.

       -M path, --manpath=path
              Specify  an alternate manpath to use.  By default, man uses man‐
              path derived code to determine the path to search.  This  option
              overrides the $MANPATH environment variable and causes option -m
              to be ignored.

              A path specified as a manpath must be the root of a manual  page
              hierarchy  structured  into  sections as described in the man-db
              manual (under "The manual page system").  To view  manual  pages
              outside such hierarchies, see the -l option.

       -S list, -s list, --sections=list
              List  is  a  colon-  or comma-separated list of `order specific'
              manual sections to search.  This option overrides  the  $MANSECT
              environment  variable.   (The  -s  spelling is for compatibility
              with System V.)

       -e sub-extension, --extension=sub-extension
              Some systems incorporate large packages of manual pages, such as
              those  that accompany the Tcl package, into the main manual page
              hierarchy.  To get around the problem of having two manual pages
              with  the  same name such as exit(3), the Tcl pages were usually
              all assigned to section l.  As this is unfortunate,  it  is  now
              possible  to put the pages in the correct section, and to assign
              a specific `extension' to them, in this case, exit(3tcl).  Under
              normal  operation,  man  will  display  exit(3) in preference to
              exit(3tcl).  To negotiate this situation and to avoid having  to
              know  which  section  the page you require resides in, it is now
              possible to give man a  sub-extension  string  indicating  which
              package  the page must belong to.  Using the above example, sup‐
              plying the option -e tcl to man  will  restrict  the  search  to
              pages having an extension of *tcl.

       -i, --ignore-case
              Ignore  case  when  searching  for  manual  pages.   This is the
              default.

       -I, --match-case
              Search for manual pages case-sensitively.

       --regex
              Show all pages with any part of  either  their  names  or  their
              descriptions  matching  each  page argument as a regular expres‐
              sion, as with apropos(1).  Since there is usually no  reasonable
              way  to  pick a "best" page when searching for a regular expres‐
              sion, this option implies -a.

       --wildcard
              Show all pages with any part of  either  their  names  or  their
              descriptions matching each page argument using shell-style wild‐
              cards, as with apropos(1) --wildcard.  The  page  argument  must
              match  the  entire  name or description, or match on word bound‐
              aries in the description.  Since there is usually no  reasonable
              way  to  pick  a "best" page when searching for a wildcard, this
              option implies -a.

       --names-only
              If the --regex or --wildcard option is  used,  match  only  page
              names,  not page descriptions, as with whatis(1).  Otherwise, no
              effect.

       -a, --all
              By default, man will exit after  displaying  the  most  suitable
              manual  page  it finds.  Using this option forces man to display
              all the manual pages with names that match the search criteria.

       -u, --update
              This option causes man to perform an `inode  level'  consistency
              check on its database caches to ensure that they are an accurate
              representation of the filesystem.  It will only  have  a  useful
              effect if man is installed with the setuid bit set.

       --no-subpages
              By default, man will try to interpret pairs of manual page names
              given on the command line as equivalent to a single manual  page
              name  containing  a hyphen.  This supports the common pattern of
              programs that implement a number of subcommands,  allowing  them
              to provide manual pages for each that can be accessed using sim‐
              ilar syntax as would be used to  invoke  the  subcommands  them‐
              selves.  For example:

                $ man -aw git diff
                /usr/share/man/man1/git-diff.1.gz

              To disable this behaviour, use the --no-subpages option.

                $ man -aw --no-subpages git diff
                /usr/share/man/man1/git.1.gz
                /usr/share/man/man3/Git.3pm.gz
                /usr/share/man/man1/diff.1.gz

   Controlling formatted output
       -P pager, --pager=pager
              Specify  which  output pager to use.  By default, man uses pager
              -s.  This option overrides the $MANPAGER  environment  variable,
              which  in turn overrides the $PAGER environment variable.  It is
              not used in conjunction with -f or -k.

              The value may be a simple command name or a command  with  argu‐
              ments, and may use shell quoting (backslashes, single quotes, or
              double quotes).  It may not use pipes to connect  multiple  com‐
              mands;  if  you  need that, use a wrapper script, which may take
              the file to display either as an argument or on standard input.

       -r prompt, --prompt=prompt
              If a recent version of less is  used  as  the  pager,  man  will
              attempt  to  set  its  prompt  and  some  sensible options.  The
              default prompt looks like

               Manual page name(sec) line x

              where name denotes the manual page name, sec denotes the section
              it  was  found  under  and  x  the current line number.  This is
              achieved by using the $LESS environment variable.

              Supplying -r with a string  will  override  this  default.   The
              string  may  contain  the text $MAN_PN which will be expanded to
              the name of the current manual page and its  section  name  sur‐
              rounded  by `(' and `)'.  The string used to produce the default
              could be expressed as

              \ Manual\ page\ \$MAN_PN\ ?ltline\ %lt?L/%L.:
              byte\ %bB?s/%s..?\ (END):?pB\ %pB\\%..

              It is broken into two lines here for  the  sake  of  readability
              only.   For its meaning see the less(1) manual page.  The prompt
              string is first evaluated by  the  shell.   All  double  quotes,
              back-quotes  and  backslashes in the prompt must be escaped by a
              preceding backslash.  The prompt string may end in an escaped  $
              which  may  be followed by further options for less.  By default
              man sets the -ix8 options.

              If you want to override  man's  prompt  string  processing  com‐
              pletely, use the $MANLESS environment variable described below.

       -7, --ascii
              When  viewing a pure ascii(7) manual page on a 7 bit terminal or
              terminal emulator, some characters  may  not  display  correctly
              when  using  the  latin1(7)  device  description with GNU nroff.
              This option allows pure ascii manual pages to  be  displayed  in
              ascii  with the latin1 device.  It will not translate any latin1
              text.  The following table  shows  the  translations  performed:
              some  parts  of it may only be displayed properly when using GNU
              nroff's latin1(7) device.


              Description           Octal   latin1   ascii
              ─────────────────────────────────────────────
              continuation hyphen    255      ‐        -
              bullet (middle dot)    267      ·        o
              acute accent           264      ´        '
              multiplication sign    327      ×        x

              If the latin1 column displays correctly, your  terminal  may  be
              set  up  for latin1 characters and this option is not necessary.
              If the latin1 and ascii columns are identical, you  are  reading
              this  page  using  this  option  or man did not format this page
              using the latin1 device description.  If the  latin1  column  is
              missing  or corrupt, you may need to view manual pages with this
              option.

              This option is ignored when using options -t, -H, -T, or -Z  and
              may be useless for nroff other than GNU's.

       -E encoding, --encoding=encoding
              Generate output for a character encoding other than the default.
              For backward compatibility, encoding may be an nroff device such
              as  ascii,  latin1, or utf8 as well as a true character encoding
              such as UTF-8.

       --no-hyphenation, --nh
              Normally, nroff will automatically hyphenate text at line breaks
              even in words that do not contain hyphens, if it is necessary to
              do so to lay out words on  a  line  without  excessive  spacing.
              This  option  disables automatic hyphenation, so words will only
              be hyphenated if they already contain hyphens.

              If you are writing a manual page  and  simply  want  to  prevent
              nroff  from hyphenating a word at an inappropriate point, do not
              use this option, but consult the  nroff  documentation  instead;
              for instance, you can put "\%" inside a word to indicate that it
              may be hyphenated at that point, or put "\%" at the start  of  a
              word to prevent it from being hyphenated.

       --no-justification, --nj
              Normally, nroff will automatically justify text to both margins.
              This option disables full justification, leaving justified  only
              to the left margin, sometimes called "ragged-right" text.

              If  you  are  writing  a  manual page and simply want to prevent
              nroff from  justifying  certain  paragraphs,  do  not  use  this
              option,   but  consult  the  nroff  documentation  instead;  for
              instance, you  can  use  the  ".na",  ".nf",  ".fi",  and  ".ad"
              requests to temporarily disable adjusting and filling.

       -p string, --preprocessor=string
              Specify  the  sequence  of  preprocessors to run before nroff or
              troff/groff.  Not all installations will have a full set of pre‐
              processors.   Some  of the preprocessors and the letters used to
              designate them are: eqn (e), grap (g), pic (p), tbl (t),  vgrind
              (v),  refer (r).  This option overrides the $MANROFFSEQ environ‐
              ment variable.  zsoelim is always run as  the  very  first  pre‐
              processor.

       -t, --troff
              Use  groff  -mandoc  to  format the manual page to stdout.  This
              option is not required in conjunction with -H, -T, or -Z.

       -T[device], --troff-device[=device]
              This option is used to change groff (or possibly troff's) output
              to  be suitable for a device other than the default.  It implies
              -t.  Examples (provided with Groff-1.17)  include  dvi,  latin1,
              ps, utf8, X75 and X100.

       -H[browser], --html[=browser]
              This  option  will  cause groff to produce HTML output, and will
              display that output in a web browser.  The choice of browser  is
              determined  by the optional browser argument if one is provided,
              by the $BROWSER  environment  variable,  or  by  a  compile-time
              default  if  that  is unset (usually lynx).  This option implies
              -t, and will only work with GNU troff.

       -X[dpi], --gxditview[=dpi]
              This option displays the output of groff in a  graphical  window
              using the gxditview program.  The dpi (dots per inch) may be 75,
              75-12, 100, or 100-12, defaulting to 75; the -12 variants use  a
              12-point  base  font.   This  option  implies  -T  with the X75,
              X75-12, X100, or X100-12 device respectively.

       -Z, --ditroff
              groff will run troff and then use an appropriate  post-processor
              to  produce  output  suitable  for  the chosen device.  If groff
              -mandoc is groff, this option is passed to groff and  will  sup‐
              press the use of a post-processor.  It implies -t.

   Getting help
       -h, --help
              Print a help message and exit.

       -V, --version
              Display version information.

EXIT STATUS
       0      Successful program execution.

       1      Usage, syntax or configuration file error.

       2      Operational error.

       3      A child process returned a non-zero exit status.

       16     At  least one of the pages/files/keywords didn't exist or wasn't
              matched.

ENVIRONMENT
       MANPATH
              If $MANPATH is set, its value is used as the path to search  for
              manual pages.

       MANROFFOPT
              The  contents of $MANROFFOPT are added to the command line every
              time man invokes the formatter (nroff, troff, or groff).

       MANROFFSEQ
              If $MANROFFSEQ is set, its value is used to determine the set of
              preprocessors  to  pass  each  manual page through.  The default
              preprocessor list is system dependent.

       MANSECT
              If $MANSECT is set, its value is a colon-delimited list of  sec‐
              tions  and  it  is  used  to  determine which manual sections to
              search and in what order.

       MANPAGER, PAGER
              If $MANPAGER or $PAGER is set ($MANPAGER is used in preference),
              its value is used as the name of the program used to display the
              manual page.  By default, pager -s is used.

              The value may be a simple command name or a command  with  argu‐
              ments, and may use shell quoting (backslashes, single quotes, or
              double quotes).  It may not use pipes to connect  multiple  com‐
              mands;  if  you  need that, use a wrapper script, which may take
              the file to display either as an argument or on standard input.

       MANLESS
              If $MANLESS is set, man will not perform any of its  usual  pro‐
              cessing  to set up a prompt string for the less pager.  Instead,
              the value of $MANLESS will be copied verbatim into  $LESS.   For
              example, if you want to set the prompt string unconditionally to
              “my prompt string”, set $MANLESS to ‘-Psmy prompt string’.

       BROWSER
              If $BROWSER is set, its value is a colon-delimited list of  com‐
              mands,  each  of  which  in  turn  is used to try to start a web
              browser for man --html.  In each command, %s is  replaced  by  a
              filename  containing  the HTML output from groff, %% is replaced
              by a single percent sign (%), and %c is replaced by a colon (:).

       SYSTEM If $SYSTEM is set, it will have the same effect  as  if  it  had
              been specified as the argument to the -m option.

       MANOPT If $MANOPT is set, it will be parsed prior to man's command line
              and is expected to be in a similar format.  As all of the  other
              man  specific  environment variables can be expressed as command
              line options, and are thus  candidates  for  being  included  in
              $MANOPT it is expected that they will become obsolete.  N.B. All
              spaces that should be interpreted as part of an  option's  argu‐
              ment must be escaped.

       MANWIDTH
              If  $MANWIDTH  is  set, its value is used as the line length for
              which manual pages should be formatted.  If it is not set,  man‐
              ual  pages  will  be formatted with a line length appropriate to
              the current terminal (using an ioctl(2) if available, the  value
              of  $COLUMNS,  or  falling  back  to 80 characters if neither is
              available).  Cat pages will only be saved when the default  for‐
              matting  can  be  used, that is when the terminal line length is
              between 66 and 80 characters.

       MAN_KEEP_FORMATTING
              Normally, when output is not being directed to a terminal  (such
              as  to a file or a pipe), formatting characters are discarded to
              make it easier to read the result without special  tools.   How‐
              ever,  if  $MAN_KEEP_FORMATTING  is  set to any non-empty value,
              these formatting characters are retained.  This  may  be  useful
              for  wrappers  around  man that can interpret formatting charac‐
              ters.

       MAN_KEEP_STDERR
              Normally, when output is being directed to a  terminal  (usually
              to  a  pager), any error output from the command used to produce
              formatted versions of manual pages is discarded to avoid  inter‐
              fering  with  the pager's display.  Programs such as groff often
              produce relatively  minor  error  messages  about  typographical
              problems  such as poor alignment, which are unsightly and gener‐
              ally confusing when displayed along with the manual page.   How‐
              ever,   some   users   want   to   see   them   anyway,  so,  if
              $MAN_KEEP_STDERR is set to any  non-empty  value,  error  output
              will be displayed as usual.

       LANG, LC_MESSAGES
              Depending  on system and implementation, either or both of $LANG
              and $LC_MESSAGES will be interrogated for  the  current  message
              locale.  man will display its messages in that locale (if avail‐
              able).  See setlocale(3) for precise details.

FILES
       /etc/manpath.config
              man-db configuration file.

       /usr/share/man
              A global manual page hierarchy.

       /usr/share/man/index.(bt|db|dir|pag)
              A traditional global index database cache.

       /var/cache/man/index.(bt|db|dir|pag)
              An FHS compliant global index database cache.

SEE ALSO
       mandb(8), manpath(1),  manpath(5),  apropos(1),  whatis(1),  catman(8),
       less(1),   nroff(1),   troff(1),  groff(1),  zsoelim(1),  setlocale(3),
       man(7), ascii(7), latin1(7), the man-db package manual, FSSTND.

HISTORY
       1990, 1991 - Originally written by John W. Eaton (jwe@che.utexas.edu).

       Dec 23 1992: Rik Faith (faith@cs.unc.edu) applied bug fixes supplied by
       Willem Kasdorp (wkasdo@nikhefk.nikef.nl).

       30th April 1994 - 23rd February 2000: Wilf. (G.Wilford@ee.surrey.ac.uk)
       has been developing and maintaining this package with the help of a few
       dedicated people.

       30th   October   1996   -  30th  March  2001:  Fabrizio  Polacco   maintained and enhanced this package for  the  Debian
       project, with the help of all the community.

       31st  March  2001  - present day: Colin Watson  is
       now developing and maintaining man-db.



2.5.7                             2010-02-16                            MAN(1)