Provided by: man-db_2.9.1-1_amd64 bug


       man - an interface to the system reference manuals


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


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

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

       1   Executable programs or shell commands
       2   System calls (functions provided by the kernel)
       3   Library calls (functions within program libraries)
       4   Special files (usually found in /dev)
       5   File formats and conventions, e.g. /etc/passwd
       6   Games
       7   Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7)
       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,

       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 man.7
           Display the manual page for macro package man from section 7.  (This is an alternative
           spelling of "man 7 man".)

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

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

       man -t bash | lpr -Pps
           Format  the manual page for bash into the default troff or groff 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

       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.


       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.

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

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


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

       If you find that the translations supplied with this package are  not  available  in  your
       native  language and you would like to supply them, please contact the maintainer who will
       be coordinating such activity.

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

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


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

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

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

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

       '\" <string>

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

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

       A  formatting  pipeline  is  formed  from  the filters and the primary 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 ~/.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.

              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 page, but do print the location of the source
              nroff file that would be formatted.  If the -a option is also used, then print  the
              locations of all source files that match the search criteria.

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

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

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

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

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

   Finding manual pages
       -L locale, --locale=locale
              man will normally determine your current  locale  by  a  call  to  the  C  function
              setlocale(3)  which  interrogates various environment variables, possibly including
              $LC_MESSAGES and $LANG.  To 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
              The given list is a colon- or comma-separated list of sections, used  to  determine
              which  manual  sections  to  search  and  in what order.  This option overrides the
              $MANSECT environment variable.  (The -s spelling is for compatibility  with  System

       -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.

              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 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 update its database caches of installed manual pages.
              This is only needed in rare situations, and it is normally better to  run  mandb(8)

              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

                $ 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, falling back to cat
              if  pager  is  not found or is not executable.  This option overrides the $MANPAGER
              environment variable, which in turn overrides the $PAGER environment variable.   It
              is not used in conjunction with -f or -k.

              The  value  may  be  a simple command name or a command with 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

              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 hyphen    255      ‐        -
              bullet (middle dot)    267      •        o
              acute accent           264      ´        '
              multiplication sign    327      ×        x

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

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

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

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

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

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

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

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

              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 matched.


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

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

              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  3am 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 is
              used, falling back to cat if pager is not found or is not executable.

              The value may be a simple command name or a command with  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, and
              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 characters.

              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

              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.


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

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


       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.