Provided by: man-db_2.7.6.1-1_amd64 bug

NAME

       man - an interface to the on-line reference manuals

SYNOPSIS

       man  [-C  file]  [-d]  [-D]  [--warnings[=warnings]]  [-R encoding] [-L
       locale] [-m system[,...]] [-M path] [-S list]  [-e  extension]  [-i|-I]
       [--regex|--wildcard]   [--names-only]  [-a]  [-u]  [--no-subpages]  [-P
       pager]   [-r   prompt]   [-7]    [-E    encoding]    [--no-hyphenation]
       [--no-justification]   [-p   string]  [-t]  [-T[device]]  [-H[browser]]
       [-X[dpi]] [-Z] [[section] page[.section] ...] ...
       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]

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 ("1 n l 8 3 2 3posix 3pm 3perl
       3am 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,
       DESCRIPTION,  OPTIONS,  EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT,
       FILES, VERSIONS, CONFORMING TO,  NOTES,  BUGS,  EXAMPLE,  AUTHORS,  and
       SEE ALSO.

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

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

       argument ...       argument is repeatable.
       [expression] ...   entire expression within [ ] is repeatable.

       Exact rendering may vary depending on the output device.  For instance,
       man  will  usually  not  be  able  to  render italics when running in a
       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.

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.

       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 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,
       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
       databases.

       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:

       <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.

       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.

DEFAULTS

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

OPTIONS

       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
              ~/.manpath.

       -d, --debug
              Print debugging information.

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

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

   Main modes of operation
       -f, --whatis
              Equivalent  to  whatis.   Display  a  short description from the
              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.

              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.   Searching  the  rendered  text
              would be much slower.

       -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
              hierarchy.

   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
              default.

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

       --regex
              Show  all  pages  with  any  part of either their names or their
              descriptions  matching  each  page   argument   as   a   regular
              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
              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.

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

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

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

       --no-subpages
              By default, man will try to interpret pairs of manual page names
              given  on the command line as equivalent to a single manual page
              name containing a hyphen 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
                /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.
              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
              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  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      ‐        -
              hyphen
              bullet (middle    267      ·        o
              dot)
              acute accent      264      ´        '
              multiplication    327      ×        x
              sign

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

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

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

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

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

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

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

       -p string, --preprocessor=string
              Specify  the  sequence  of  preprocessors to run before nroff or
              troff/groff.  Not all installations will  have  a  full  set  of
              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
              preprocessor.

       -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.

       --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.

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

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

       MANSECT
              If $MANSECT is set, its  value  is  a  colon-delimited  list  of
              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  3am  5  4  9  6 7", unless overridden by the SECTION
              directive 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.

              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.

       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
              environment variable.

       BROWSER
              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.

       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, 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.

       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.
              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
              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
              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.

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

FILES

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

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

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

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

SEE ALSO

       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

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@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.