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       man - an interface to the on-line reference manuals


       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-justification]   [-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 [-?V]


       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 ("1 n l 8 3 2 3posix 3pm 3perl 5
       4 9 6 7" by default, unless overridden  by  the  SECTION  directive  in
       /etc/manpath.config),  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  conventions), 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,
       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
       terminal, 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
       several exclusive invocations as is shown in the  SYNOPSIS  section  of
       this manual page.


       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
           successive displays or skip any of them.

       man -t alias | lpr -Pps
           Format  the  manual  page  referenced  by  `alias', usually a shell
           manual page, into the default troff or groff format 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 -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.


       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,
       section  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
       (preceded 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

       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
       compile 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
       Hierarchy  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
       coordinating such activity.

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


       man  will search for the desired manual pages within the index database
       caches. If the -u  option  is  given,  a  cache  consistency  check  is
       performed  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  database  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
       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

       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
       formatter  (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.


       Non argument options that are duplicated either on the command line, in
       $MANOPT, or both,  are  not  harmful.   For  options  that  require  an
       argument, 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

       -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.

              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
              manual page, if available.  See whatis(1) for details.

       -k, --apropos
              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.

       -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, --path, --location
              Don't actually display  the  manual  pages,  but  do  print  the
              location(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
              location(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
              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 installed in  a  structure  similar  to  a  manual  page

   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
              temporarily 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
              operating  system's manual pages, include the system name man in
              the argument string.  This  option  will  override  the  $SYSTEM
              environment variable.

       -M path, --manpath=path
              Specify  an  alternate  manpath  to  use.   By default, man uses
              manpath 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,
              supplying 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

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

              Show all pages with any part of  either  their  names  or  their
              descriptions   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.

              Show all pages with any part of  either  their  names  or  their
              descriptions  matching  each  page  argument  using  shell-style
              wildcards, 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 implies -a.

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

       -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.

              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
              subcommands, allowing them to provide manual pages for each that
              can be accessed using similar syntax as would be used to  invoke
              the subcommands themselves.  For example:

                $ man -aw git diff

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

                $ man -aw --no-subpages git diff

   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
              arguments,  and  may  use  shell  quoting  (backslashes,  single
              quotes, or double quotes).  It may  not  use  pipes  to  connect
              multiple commands; 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
              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
              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.

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

       -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      255      ‐        -
              bullet (middle    267      ·        o
              acute accent      264      ´        '
              multiplication    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

              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
              preprocessors.  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
              environment  variable.   zsoelim is always run as the very first

       -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
              suppress the use of a post-processor.  It implies -t.

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

              Print a short usage message and exit.

       -V, --version
              Display version information.


       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


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

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

              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.

              If  $MANSECT  is  set,  its  value  is a colon-delimited list of
              sections and it is used to determine which  manual  sections  to
              search  and  in  what order.  The default is "1 n l 8 3 2 3posix
              3pm 3perl 5 4 9 6 7", unless overridden by the SECTION directive
              in /etc/manpath.config.

              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
              arguments,  and  may  use  shell  quoting  (backslashes,  single
              quotes,  or  double  quotes).   It  may not use pipes to connect
              multiple commands; if you need that, use a wrapper script, which
              may  take  the  file  to  display  either  as  an argument or on
              standard input.

              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
              environment variable.

              If $BROWSER is set, its  value  is  a  colon-delimited  list  of
              commands,  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.

              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,  an  ioctl(2)
              if  available,  or  falling  back to 80 characters if neither is
              available).  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.

              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.
              However,  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

              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
              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.

              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
              available).  See setlocale(3) for precise details.


              man-db configuration file.

              A global manual page hierarchy.

              A traditional global index database cache.

              An FHS compliant global index database cache.


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


       1990, 1991 – Originally written by John W. Eaton (

       Dec 23 1992: Rik Faith ( applied bug fixes supplied by
       Willem Kasdorp (

       30th April 1994 – 23rd February 2000: Wilf. (
       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.

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