man manpage

Search topic Section

MAN(1)			      Manual pager utils			MAN(1)

       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-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 [-?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 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 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.

       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.

       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-

       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.

       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

       '\" <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  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.

       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

       -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 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

       -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	 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-

   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

       -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 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.

	      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.

	      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  subcom-
	      mands,  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 less
	      -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\\%..
	      (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.

	      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	  255	   -	    -
	      bullet   (middle	  267	   o	    o
	      acute accent	  264	   '	    '
	      multiplication	  327	   x	    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 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-

       -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
       -?, --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 sec-
	      tions and it is used  to	determine  which  manual  sections  to
	      search and in what order.

	      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, less -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.

	      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'.

	      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.

	      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.

	      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-

	      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.

	      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.

	      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 (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	 <fpo-
       lacco@debian.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.

2.6.3				  2012-09-17				MAN(1)