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MAN(1)                         Manual pager utils                        MAN(1)

NAME
       man - an interface to the system reference manuals

SYNOPSIS
       man [man options] [[section] page ...] ...
       man -k [apropos options] regexp ...
       man -K [man options] [section] term ...
       man -f [whatis options] page ...
       man -l [man options] file ...
       man -w|-W [man options] page ...

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 (see DEFAULTS), 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, e.g. /etc/passwd
       6   Games
       7   Miscellaneous  (including  macro  packages  and  conventions),  e.g.
           man(7), groff(7), man-pages(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, DE-
       SCRIPTION,  OPTIONS,  EXIT STATUS,  RETURN VALUE,  ERRORS,  ENVIRONMENT,
       FILES, VERSIONS, STANDARDS, 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 man.7
           Display the manual page for macro package man from section 7.  (This
           is an alternative spelling of "man 7 man".)

       man 'man(7)'
           Display the manual page for macro package man from section 7.  (This
           is another alternative spelling of "man 7 man".  It may be more con-
           venient  when  copying and pasting cross-references to manual pages.
           Note that the parentheses must normally be quoted  to  protect  them
           from the shell.)

       man -a intro
           Display, in succession, all of the available intro manual pages con-
           tained within the manual.  It is possible to quit between successive
           displays or skip any of them.

       man -t bash | lpr -Pps
           Format the manual page for bash into the default troff or groff for-
           mat  and  pipe  it  to the printer named ps.  The default output for
           groff is usually PostScript.  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 redirection
           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 printf.

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

       Manual  pages  are  normally stored in nroff(1) format under a directory
       such as /usr/share/man.  In some installations, there may also  be  pre-
       formatted  cat pages to improve performance.  See manpath(5) for details
       of where these files are stored.

       This package supports manual pages in multiple languages, controlled  by
       your  locale.  If your system did not set this up for you automatically,
       then you may need to set $LC_MESSAGES, $LANG, or  another  system-depen-
       dent  environment  variable  to  indicate your preferred locale, usually
       specified in the POSIX format:

       <language>[_<territory>[.<character-set>[,<version>]]]

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

       If you find that the translations 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 coordinating such activity.

       Individual manual pages are normally written and maintained by the main-
       tainers of the program, function, or other topic that they document, and
       are not included with this package.  If you find that a manual  page  is
       missing  or  inadequate,  please  report  that to the maintainers of the
       package in question.

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

DEFAULTS
       The  order  of  sections  to search may be overridden by the environment
       variable $MANSECT or by the SECTION  directive  in  /etc/manpath.config.
       By default it is as follows:

              1 n l 8 3 0 2 3type 3posix 3pm 3perl 3am 5 4 9 6 7

       The formatted manual page is displayed using a pager.  This can be spec-
       ified  in a number of ways, or else will fall back to a default (see op-
       tion -P for details).

       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 initial
       line of the nroff file is parsed for a preprocessor string.  To  contain
       a valid preprocessor string, the first line must resemble

       '\" <string>

       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 format-
       ter (nroff or [tg]roff with -t) and executed.  Alternatively, if an exe-
       cutable  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 re-
              sets man's behaviour to its default.  Its use is to  reset  those
              options that may have been set in $MANOPT.  Any options that fol-
              low -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 de-
              fault is "mac".  To disable a groff warning, prefix it with  "!":
              for  example, --warnings=mac,!break enables warnings in the "mac"
              category and disables warnings in the "break" category.  See  the
              “Warnings”  node  in  info  groff for a list of available warning
              names.

   Main modes of operation
       -f, --whatis
              Approximately equivalent to whatis.  Display a short  description
              from the manual page, if available.  See whatis(1) for details.

       -k, --apropos
              Approximately  equivalent  to  apropos.   Search the short manual
              page descriptions 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.

              Note  that this searches the sources of the manual pages, not the
              rendered text, and so may include false positives due  to  things
              like  comments  in source files, or false negatives due to things
              like hyphens being written as "\-" in  source  files.   Searching
              the rendered text would be much slower.

       -l, --local-file
              Activate "local" mode.  Format and display local manual files in-
              stead  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.

              If this option is not used, then man will also fall back  to  in-
              terpreting manual page arguments as local file names if the argu-
              ment  contains  a  "/" character, since that is a good indication
              that the argument refers to a path on the file system.

       -w, --where, --path, --location
              Don't actually display the manual page, but do print the location
              of the source nroff file that would be formatted.  If the -a  op-
              tion  is  also used, then print the locations of all source files
              that match the search criteria.

       -W, --where-cat, --location-cat
              Don't actually display the manual page, but do print the location
              of the preformatted cat file that would be displayed.  If the  -a
              option is also used, then print the locations of all preformatted
              cat files that match the search criteria.

              If  -w  and -W are both used, then print both source file and cat
              file separated by a space.  If all of -w, -W, and  -a  are  used,
              then do this for each possible match.

       -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 manconv(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 in-
              stalled in a structure similar to a manual page hierarchy.

              Consider using man-recode(1) instead for converting multiple man-
              ual pages, since it has an interface designed for bulk conversion
              and so can be much faster.

   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  tem-
              porarily override the determined value, use this option to supply
              a  locale string directly to man.  Note that it will not take ef-
              fect until the search for pages actually begins.  Output such  as
              the help message will always be displayed in the initially deter-
              mined locale.

       -m system[,...], --systems=system[,...]
              If  this  system  has  access  to other operating systems' 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  op-
              erating  system names.  To include a search of the native operat-
              ing system's manual pages, include the system name man in the ar-
              gument string.  This option will override the $SYSTEM environment
              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
              The given list is a colon- or comma-separated list  of  sections,
              used to determine which manual sections to search and in what or-
              der.   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 de-
              fault.

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

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

       --wildcard
              Show all pages with any part of either their names or  their  de-
              scriptions  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 boundaries
              in  the description.  Since there is usually no reasonable way to
              pick a "best" page when searching for a wildcard, this option im-
              plies -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 man-
              ual 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 update its database caches of installed
              manual  pages.  This is only needed in rare situations, and it is
              normally better to run mandb(8) instead.

       --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 or an  underscore.   This  supports  the
              common  pattern  of  programs  that implement a number of subcom-
              mands, allowing them to provide manual pages for each that can be
              accessed using similar syntax as would be used to invoke the sub-
              commands themselves.  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,
              falling  back  to cat if pager is not found or is not executable.
              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 at-
              tempt 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  surrounded
              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\\%..
              (press h for help or q to quit)

              It is broken into three 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 preced-
              ing 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.

              The  $MANLESS environment variable described below may be used to
              set a default prompt string if none is supplied  on  the  command
              line.

       -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  op-
              tion 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  hy-
              phenated 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 in-
              stance, 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  op-
              tion 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 (as of groff 1.23.0) include dvi, latin1, pdf, 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 de-
              fault 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 -man-
              doc  is  groff,  this option is passed to groff and will suppress
              the use of a post-processor.  It implies -t.

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

       --usage
              Print a short usage 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.

              See the SEARCH PATH section of manpath(5) for the default  behav-
              iour and details of how this environment variable is handled.

       MANROFFOPT
              Every time man invokes the formatter (nroff, troff, or groff), it
              adds the contents of $MANROFFOPT to the formatter's command line.

              For  example,  MANROFFOPT=-P-i  tells the formatter to use italic
              text (which is only supported by some terminals) rather than  un-
              derlined text.

       MANROFFSEQ
              If  $MANROFFSEQ is set, its value is used to determine the set of
              preprocessors to pass each manual page through.  The default pre-
              processor 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.  The default is "1 n l 8 3 0 2 3type 3posix
              3pm 3perl 3am 5 4 9 6 7", unless overridden by the SECTION direc-
              tive in /etc/manpath.config.

       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 is used, falling back to  cat  if
              pager is not found or is not executable.

              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, its value will be used as the default  prompt
              string  for the less pager, as if it had been passed using the -r
              option (so any occurrences of the text $MAN_PN will  be  expanded
              in  the  same  way).   For example, if you want to set the prompt
              string unconditionally to “my prompt  string”,  set  $MANLESS  to
              ‘-Psmy prompt string’.   Using the -r option overrides this envi-
              ronment variable.

       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 argument
              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, manual
              pages will be formatted with a line  length  appropriate  to  the
              current  terminal  (using  the value of $COLUMNS, and ioctl(2) if
              available, or falling back to 80 characters if neither is  avail-
              able).   Cat pages will only be saved when the default formatting
              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 characters.

       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 for-
              matted versions of manual pages is discarded to avoid interfering
              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 generally confusing
              when displayed along with the manual page.  However,  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.

       MAN_DISABLE_SECCOMP
              On Linux, man normally  confines  subprocesses  that  handle  un-
              trusted  data using a seccomp(2) sandbox.  This makes it safer to
              run complex parsing code over arbitrary manual  pages.   If  this
              goes  wrong  for some reason unrelated to the content of the page
              being displayed, you can set  $MAN_DISABLE_SECCOMP  to  any  non-
              empty value to disable the sandbox.

       PIPELINE_DEBUG
              If  the  $PIPELINE_DEBUG environment variable is set to "1", then
              man will print debugging messages to  standard  error  describing
              each subprocess it runs.

       LANG, LC_MESSAGES
              Depending  on  system and implementation, either or both of $LANG
              and $LC_MESSAGES will be interrogated for the current message lo-
              cale.  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.

STANDARDS
       POSIX.1-2001, POSIX.1-2008, POSIX.1-2017.

SEE ALSO
       apropos(1),   groff(1),   less(1),   manpath(1),   nroff(1),   troff(1),
       whatis(1), zsoelim(1), manpath(5), man(7), catman(8), mandb(8)

       Documentation for some packages may be available in other formats,  such
       as info(1) or HTML.

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  <fpolacco@de-
       bian.org>  maintained  and enhanced this package for the Debian project,
       with the help of all the community.

       31st March 2001 – present day: Colin Watson <cjwatson@debian.org> is now
       developing and maintaining man-db.

BUGS
       https://gitlab.com/man-db/man-db/-/issues
       https://savannah.nongnu.org/bugs/?group=man-db

2.13.1                             2025-05-02                            MAN(1)

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