1MAN(1)                        Manual pager utils                        MAN(1)


6       man - an interface to the on-line reference manuals


9       man  [-C  file]  [-d]  [-D]  [--warnings[=warnings]]  [-R encoding] [-L
10       locale] [-m system[,...]] [-M path] [-S list]  [-e  extension]  [-i|-I]
11       [--regex|--wildcard]   [--names-only]  [-a]  [-u]  [--no-subpages]  [-P
12       pager] [-r prompt] [-7] [-E encoding] [--no-hyphenation] [--no-justifi‐
13       cation]  [-p  string]  [-t]  [-T[device]]  [-H[browser]] [-X[dpi]] [-Z]
14       [[section] page[.section] ...] ...
15       man -k [apropos options] regexp ...
16       man -K [-w|-W] [-S list] [-i|-I] [--regex] [section] term ...
17       man -f [whatis options] page ...
18       man -l [-C file] [-d] [-D] [--warnings[=warnings]]  [-R  encoding]  [-L
19       locale]  [-P  pager]  [-r  prompt]  [-7] [-E encoding] [-p string] [-t]
20       [-T[device]] [-H[browser]] [-X[dpi]] [-Z] file ...
21       man -w|-W [-C file] [-d] [-D] page ...
22       man -c [-C file] [-d] [-D] page ...
23       man [-?V]


26       man is the system's manual pager.  Each page argument given to  man  is
27       normally  the  name of a program, utility or function.  The manual page
28       associated with each of these arguments is then found and displayed.  A
29       section,  if  provided, will direct man to look only in that section of
30       the manual.  The default action is to search in all  of  the  available
31       sections following a pre-defined order ("1 1p 8 2 3 3p 3pm 4 5 6 7 9 0p
32       n l p o 1x 2x 3x 4x 5x 6x 7x 8x" by default, unless overridden  by  the
33       SECTION directive in /etc/man_db.conf), and to show only the first page
34       found, even if page exists in several sections.
36       The table below shows the section numbers of the manual followed by the
37       types of pages they contain.
40       1   Executable programs or shell commands
41       2   System calls (functions provided by the kernel)
42       3   Library calls (functions within program libraries)
43       4   Special files (usually found in /dev)
44       5   File formats and conventions eg /etc/passwd
45       6   Games
46       7   Miscellaneous  (including  macro  packages  and  conventions), e.g.
47           man(7), groff(7)
48       8   System administration commands (usually only for root)
49       9   Kernel routines [Non standard]
51       A manual page consists of several sections.
53       Conventional  section  names  include  NAME,  SYNOPSIS,  CONFIGURATION,
56       SEE ALSO.
58       The following conventions apply to the SYNOPSIS section and can be used
59       as a guide in other sections.
62       bold text          type exactly as shown.
63       italic text        replace with appropriate argument.
64       [-abc]             any or all arguments within [ ] are optional.
65       -a|-b              options delimited by | cannot be used together.
67       argument ...       argument is repeatable.
68       [expression] ...   entire expression within [ ] is repeatable.
70       Exact rendering may vary depending on the output device.  For instance,
71       man will usually not be able to render italics when running in a termi‐
72       nal, and will typically use underlined or coloured text instead.
74       The command or function illustration is a pattern that should match all
75       possible invocations.  In some cases it is advisable to illustrate sev‐
76       eral exclusive invocations as is shown in the SYNOPSIS section of  this
77       manual page.


80       man ls
81           Display the manual page for the item (program) ls.
83       man man.7
84           Display the manual page for macro package man from section 7.
86       man -a intro
87           Display,  in  succession,  all  of the available intro manual pages
88           contained within the manual.  It is possible to quit  between  suc‐
89           cessive displays or skip any of them.
91       man -t alias | lpr -Pps
92           Format  the manual page referenced by `alias', usually a shell man‐
93           ual page, into the default troff or groff format and pipe it to the
94           printer  named  ps.   The default output for groff is usually Post‐
95           Script.  man --help should advise as to which processor is bound to
96           the -t option.
98       man -l -Tdvi ./foo.1x.gz > ./foo.1x.dvi
99           This  command  will  decompress  and format the nroff source manual
100           page ./foo.1x.gz into a device independent (dvi) file.   The  redi‐
101           rection is necessary as the -T flag causes output to be directed to
102           stdout with no pager.  The output could be viewed  with  a  program
103           such  as  xdvi or further processed into PostScript using a program
104           such as dvips.
106       man -k printf
107           Search the short descriptions and manual page names for the keyword
108           printf  as  regular expression.  Print out any matches.  Equivalent
109           to apropos printf.
111       man -f smail
112           Lookup the manual pages referenced by smail and print out the short
113           descriptions of any found.  Equivalent to whatis smail.


116       Many  options are available to man in order to give as much flexibility
117       as possible to the user.  Changes can be made to the search path,  sec‐
118       tion  order,  output  processor,  and  other  behaviours and operations
119       detailed below.
121       If set, various environment variables are interrogated to determine the
122       operation  of  man.   It  is  possible  to set the `catch all' variable
123       $MANOPT to any string in command line format with  the  exception  that
124       any  spaces  used as part of an option's argument must be escaped (pre‐
125       ceded by a backslash).  man will parse $MANOPT prior to parsing its own
126       command  line.   Those options requiring an argument will be overridden
127       by the same options found on the command line.  To  reset  all  of  the
128       options set in $MANOPT, -D can be specified as the initial command line
129       option.  This will allow man to `forget' about the options specified in
130       $MANOPT although they must still have been valid.
132       The  manual  pager  utilities  packaged as man-db make extensive use of
133       index database caches.  These caches contain information such as  where
134       each  manual  page  can  be found on the filesystem and what its whatis
135       (short one line description of the man page) contains, and allow man to
136       run  faster  than  if it had to search the filesystem each time to find
137       the appropriate manual page.  If requested using  the  -u  option,  man
138       will  ensure  that  the caches remain consistent, which can obviate the
139       need to manually run software to update traditional whatis  text  data‐
140       bases.
142       If  man  cannot  find a mandb initiated index database for a particular
143       manual page hierarchy, it will still search for  the  requested  manual
144       pages,  although  file globbing will be necessary to search within that
145       hierarchy.  If whatis or apropos fails to find an index it will try  to
146       extract information from a traditional whatis database instead.
148       These  utilities  support  compressed  source  nroff  files  having, by
149       default, the extensions of .Z, .z and .gz.  It is possible to deal with
150       any  compression  extension, but this information must be known at com‐
151       pile time.  Also, by default, any cat  pages  produced  are  compressed
152       using gzip.  Each `global' manual page hierarchy such as /usr/share/man
153       or /usr/X11R6/man may have any directory as  its  cat  page  hierarchy.
154       Traditionally  the cat pages are stored under the same hierarchy as the
155       man pages, but for reasons such as those specified in the File  Hierar‐
156       chy  Standard  (FHS),  it  may  be better to store them elsewhere.  For
157       details on how to do this, please read manpath(5).  For details on  why
158       to do this, read the standard.
160       International  support is available with this package.  Native language
161       manual pages are accessible (if available on your system)  via  use  of
162       locale  functions.   To  activate  such support, it is necessary to set
163       either $LC_MESSAGES, $LANG  or  another  system  dependent  environment
164       variable to your language locale, usually specified in the POSIX 1003.1
165       based format:
167       <language>[_<territory>[.<character-set>[,<version>]]]
169       If the desired page is available in your locale, it will  be  displayed
170       in lieu of the standard (usually American English) page.
172       Support  for  international message catalogues is also featured in this
173       package and can be activated in the same way, again if  available.   If
174       you  find  that  the  manual pages and message catalogues supplied with
175       this package are not available in your native language  and  you  would
176       like  to supply them, please contact the maintainer who will be coordi‐
177       nating such activity.
179       For information regarding other features and extensions available  with
180       this manual pager, please read the documents supplied with the package.


183       man  will search for the desired manual pages within the index database
184       caches. If the -u option is given, a cache consistency  check  is  per‐
185       formed  to  ensure the databases accurately reflect the filesystem.  If
186       this option is always given, it is not generally necessary to run mandb
187       after the caches are initially created, unless a cache becomes corrupt.
188       However, the cache consistency check can be slow on systems  with  many
189       manual  pages  installed, so it is not performed by default, and system
190       administrators may wish to run mandb every week or so to keep the data‐
191       base  caches  fresh.   To forestall problems caused by outdated caches,
192       man will fall back to file globbing if a cache lookup fails, just as it
193       would if no cache was present.
195       Once  a  manual page has been located, a check is performed to find out
196       if a relative preformatted `cat' file already exists and is newer  than
197       the nroff file.  If it does and is, this preformatted file is (usually)
198       decompressed and then displayed, via use of a pager.  The pager can  be
199       specified  in  a number of ways, or else will fall back to a default is
200       used (see option -P for details).  If no cat is found or is older  than
201       the  nroff  file, the nroff is filtered through various programs and is
202       shown immediately.
204       If a cat file can be produced (a relative cat directory exists and  has
205       appropriate  permissions),  man will compress and store the cat file in
206       the background.
208       The filters are deciphered by a number of means.  Firstly, the  command
209       line option -p or the environment variable $MANROFFSEQ is interrogated.
210       If -p was not used and the environment variable was not set,  the  ini‐
211       tial  line  of  the nroff file is parsed for a preprocessor string.  To
212       contain a valid preprocessor string, the first line must resemble
214       '\" <string>
216       where string can be any combination of letters described by  option  -p
217       below.
219       If  none of the above methods provide any filter information, a default
220       set is used.
222       A formatting pipeline is formed from the filters and the  primary  for‐
223       matter  (nroff or [tg]roff with -t) and executed.  Alternatively, if an
224       executable program mandb_nfmt (or mandb_tfmt with -t) exists in the man
225       tree  root,  it  is executed instead.  It gets passed the manual source
226       file, the preprocessor string, and optionally the device specified with
227       -T or -E as arguments.


230       Non argument options that are duplicated either on the command line, in
231       $MANOPT, or both, are not harmful.  For options that require  an  argu‐
232       ment, each duplication will override the previous argument value.
234   General options
235       -C file, --config-file=file
236              Use  this  user  configuration  file  rather than the default of
237              ~/.manpath.
239       -d, --debug
240              Print debugging information.
242       -D, --default
243              This option is normally issued as  the  very  first  option  and
244              resets  man's  behaviour  to  its  default.  Its use is to reset
245              those options that may have been set in  $MANOPT.   Any  options
246              that follow -D will have their usual effect.
248       --warnings[=warnings]
249              Enable  warnings from groff.  This may be used to perform sanity
250              checks on the source text of manual pages.  warnings is a comma-
251              separated  list  of  warning  names;  if it is not supplied, the
252              default is "mac".  See the “Warnings” node in info groff  for  a
253              list of available warning names.
255   Main modes of operation
256       -f, --whatis
257              Equivalent to whatis.  Display a short description from the man‐
258              ual page, if available.  See whatis(1) for details.
260       -k, --apropos
261              Equivalent to apropos.  Search the short  manual  page  descrip‐
262              tions  for keywords and display any matches.  See apropos(1) for
263              details.
265       -K, --global-apropos
266              Search for text in all manual  pages.   This  is  a  brute-force
267              search,  and is likely to take some time; if you can, you should
268              specify a section to reduce the number of pages that need to  be
269              searched.   Search terms may be simple strings (the default), or
270              regular expressions if the --regex option is used.
272              Note that this searches the sources of the manual pages, not the
273              rendered  text, and so may include false positives due to things
274              like comments in source  files.   Searching  the  rendered  text
275              would be much slower.
277       -l, --local-file
278              Activate  `local'  mode.   Format and display local manual files
279              instead of searching through  the  system's  manual  collection.
280              Each manual page argument will be interpreted as an nroff source
281              file in the correct format.  No cat file is produced.  If '-' is
282              listed  as one of the arguments, input will be taken from stdin.
283              When this option is not used, and man fails  to  find  the  page
284              required,  before  displaying  the error message, it attempts to
285              act as if this option was supplied, using the name as a filename
286              and looking for an exact match.
288       -w, --where, --path, --location
289              Don't  actually display the manual pages, but do print the loca‐
290              tion(s) of the source nroff files that would be formatted.
292       -W, --where-cat, --location-cat
293              Don't actually display the manual pages, but do print the  loca‐
294              tion(s)  of the cat files that would be displayed.  If -w and -W
295              are both specified, print both separated by a space.
297       -c, --catman
298              This option is not for general use and should only  be  used  by
299              the catman program.
301       -R encoding, --recode=encoding
302              Instead  of  formatting the manual page in the usual way, output
303              its source converted to the specified encoding.  If you  already
304              know  the  encoding  of  the  source file, you can also use man‐
305              conv(1) directly.  However, this option allows  you  to  convert
306              several  manual  pages  to  a  single encoding without having to
307              explicitly state the encoding of each, provided that  they  were
308              already  installed in a structure similar to a manual page hier‐
309              archy.
311   Finding manual pages
312       -L locale, --locale=locale
313              man will normally determine your current locale by a call to the
314              C  function  setlocale(3) which interrogates various environment
315              variables, possibly including $LC_MESSAGES and $LANG.  To tempo‐
316              rarily  override the determined value, use this option to supply
317              a locale string directly to man.  Note that  it  will  not  take
318              effect  until the search for pages actually begins.  Output such
319              as the help message will always be displayed  in  the  initially
320              determined locale.
322       -m system[,...], --systems=system[,...]
323              If  this  system  has  access to other operating system's manual
324              pages, they can be accessed using this option.  To search for  a
325              manual  page from NewOS's manual page collection, use the option
326              -m NewOS.
328              The system specified can be a  combination  of  comma  delimited
329              operating system names.  To include a search of the native oper‐
330              ating system's manual pages, include the system name man in  the
331              argument string.  This option will override the $SYSTEM environ‐
332              ment variable.
334       -M path, --manpath=path
335              Specify an alternate manpath to use.  By default, man uses  man‐
336              path  derived code to determine the path to search.  This option
337              overrides the $MANPATH environment variable and causes option -m
338              to be ignored.
340              A  path specified as a manpath must be the root of a manual page
341              hierarchy structured into sections as described  in  the  man-db
342              manual  (under  "The manual page system").  To view manual pages
343              outside such hierarchies, see the -l option.
345       -S list, -s list, --sections=list
346              List is a colon- or comma-separated  list  of  `order  specific'
347              manual  sections  to search.  This option overrides the $MANSECT
348              environment variable.  (The -s  spelling  is  for  compatibility
349              with System V.)
351       -e sub-extension, --extension=sub-extension
352              Some systems incorporate large packages of manual pages, such as
353              those that accompany the Tcl package, into the main manual  page
354              hierarchy.  To get around the problem of having two manual pages
355              with the same name such as exit(3), the Tcl pages  were  usually
356              all  assigned  to  section l.  As this is unfortunate, it is now
357              possible to put the pages in the correct section, and to  assign
358              a specific `extension' to them, in this case, exit(3tcl).  Under
359              normal operation, man will  display  exit(3)  in  preference  to
360              exit(3tcl).   To negotiate this situation and to avoid having to
361              know which section the page you require resides in,  it  is  now
362              possible  to  give  man  a sub-extension string indicating which
363              package the page must belong to.  Using the above example,  sup‐
364              plying  the  option  -e tcl  to  man will restrict the search to
365              pages having an extension of *tcl.
367       -i, --ignore-case
368              Ignore case when  searching  for  manual  pages.   This  is  the
369              default.
371       -I, --match-case
372              Search for manual pages case-sensitively.
374       --regex
375              Show  all  pages  with  any  part of either their names or their
376              descriptions matching each page argument as  a  regular  expres‐
377              sion,  as with apropos(1).  Since there is usually no reasonable
378              way to pick a "best" page when searching for a  regular  expres‐
379              sion, this option implies -a.
381       --wildcard
382              Show  all  pages  with  any  part of either their names or their
383              descriptions matching each page argument using shell-style wild‐
384              cards,  as  with  apropos(1) --wildcard.  The page argument must
385              match the entire name or description, or match  on  word  bound‐
386              aries  in the description.  Since there is usually no reasonable
387              way to pick a "best" page when searching for  a  wildcard,  this
388              option implies -a.
390       --names-only
391              If  the  --regex  or  --wildcard option is used, match only page
392              names, not page descriptions, as with whatis(1).  Otherwise,  no
393              effect.
395       -a, --all
396              By  default,  man  will  exit after displaying the most suitable
397              manual page it finds.  Using this option forces man  to  display
398              all the manual pages with names that match the search criteria.
400       -u, --update
401              This  option  causes man to perform an `inode level' consistency
402              check on its database caches to ensure that they are an accurate
403              representation  of  the  filesystem.  It will only have a useful
404              effect if man is installed with the setuid bit set.
406       --no-subpages
407              By default, man will try to interpret pairs of manual page names
408              given  on the command line as equivalent to a single manual page
409              name containing a hyphen or an underscore.   This  supports  the
410              common  pattern  of  programs that implement a number of subcom‐
411              mands, allowing them to provide manual pages for each  that  can
412              be  accessed using similar syntax as would be used to invoke the
413              subcommands themselves.  For example:
415                $ man -aw git diff
416                /usr/share/man/man1/git-diff.1.gz
418              To disable this behaviour, use the --no-subpages option.
420                $ man -aw --no-subpages git diff
421                /usr/share/man/man1/git.1.gz
422                /usr/share/man/man3/Git.3pm.gz
423                /usr/share/man/man1/diff.1.gz
425   Controlling formatted output
426       -P pager, --pager=pager
427              Specify which output pager to use.  By default, man  uses  less,
428              falling  back  to cat if less is not found or is not executable.
429              This option overrides the $MANPAGER environment variable,  which
430              in  turn  overrides  the $PAGER environment variable.  It is not
431              used in conjunction with -f or -k.
433              The value may be a simple command name or a command  with  argu‐
434              ments, and may use shell quoting (backslashes, single quotes, or
435              double quotes).  It may not use pipes to connect  multiple  com‐
436              mands;  if  you  need that, use a wrapper script, which may take
437              the file to display either as an argument or on standard input.
439       -r prompt, --prompt=prompt
440              If a recent version of less is  used  as  the  pager,  man  will
441              attempt  to  set  its  prompt  and  some  sensible options.  The
442              default prompt looks like
444               Manual page name(sec) line x
446              where name denotes the manual page name, sec denotes the section
447              it  was  found  under  and  x  the current line number.  This is
448              achieved by using the $LESS environment variable.
450              Supplying -r with a string  will  override  this  default.   The
451              string  may  contain  the text $MAN_PN which will be expanded to
452              the name of the current manual page and its  section  name  sur‐
453              rounded  by `(' and `)'.  The string used to produce the default
454              could be expressed as
456              \ Manual\ page\ \$MAN_PN\ ?ltline\ %lt?L/%L.:
457              byte\ %bB?s/%s..?\ (END):?pB\ %pB\\%..
458              (press h for help or q to quit)
460              It is broken into three lines here for the sake  of  readability
461              only.   For its meaning see the less(1) manual page.  The prompt
462              string is first evaluated by  the  shell.   All  double  quotes,
463              back-quotes  and  backslashes in the prompt must be escaped by a
464              preceding backslash.  The prompt string may end in an escaped  $
465              which  may  be followed by further options for less.  By default
466              man sets the -ix8 options.
468              The $MANLESS environment variable described below may be used to
469              set  a  default prompt string if none is supplied on the command
470              line.
472       -7, --ascii
473              When viewing a pure ascii(7) manual page on a 7 bit terminal  or
474              terminal  emulator,  some  characters  may not display correctly
475              when using the latin1(7)  device  description  with  GNU  nroff.
476              This  option  allows  pure ascii manual pages to be displayed in
477              ascii with the latin1 device.  It will not translate any  latin1
478              text.   The  following  table  shows the translations performed:
479              some parts of it may only be displayed properly when  using  GNU
480              nroff's latin1(7) device.
483              Description      Octal   latin1   ascii
484              ────────────────────────────────────────
485              continuation      255      ‐        -
486              hyphen
487              bullet (middle    267      ·        o
488              dot)
489              acute accent      264      ´        '
490              multiplication    327      ×        x
491              sign
493              If the latin1 column displays correctly, your  terminal  may  be
494              set  up  for latin1 characters and this option is not necessary.
495              If the latin1 and ascii columns are identical, you  are  reading
496              this  page  using  this  option  or man did not format this page
497              using the latin1 device description.  If the  latin1  column  is
498              missing  or corrupt, you may need to view manual pages with this
499              option.
501              This option is ignored when using options -t, -H, -T, or -Z  and
502              may be useless for nroff other than GNU's.
504       -E encoding, --encoding=encoding
505              Generate output for a character encoding other than the default.
506              For backward compatibility, encoding may be an nroff device such
507              as  ascii,  latin1, or utf8 as well as a true character encoding
508              such as UTF-8.
510       --no-hyphenation, --nh
511              Normally, nroff will automatically hyphenate text at line breaks
512              even in words that do not contain hyphens, if it is necessary to
513              do so to lay out words on  a  line  without  excessive  spacing.
514              This  option  disables automatic hyphenation, so words will only
515              be hyphenated if they already contain hyphens.
517              If you are writing a manual page  and  simply  want  to  prevent
518              nroff  from hyphenating a word at an inappropriate point, do not
519              use this option, but consult the  nroff  documentation  instead;
520              for instance, you can put "\%" inside a word to indicate that it
521              may be hyphenated at that point, or put "\%" at the start  of  a
522              word to prevent it from being hyphenated.
524       --no-justification, --nj
525              Normally, nroff will automatically justify text to both margins.
526              This option disables full justification, leaving justified  only
527              to the left margin, sometimes called "ragged-right" text.
529              If  you  are  writing  a  manual page and simply want to prevent
530              nroff from  justifying  certain  paragraphs,  do  not  use  this
531              option,   but  consult  the  nroff  documentation  instead;  for
532              instance, you  can  use  the  ".na",  ".nf",  ".fi",  and  ".ad"
533              requests to temporarily disable adjusting and filling.
535       -p string, --preprocessor=string
536              Specify  the  sequence  of  preprocessors to run before nroff or
537              troff/groff.  Not all installations will have a full set of pre‐
538              processors.   Some  of the preprocessors and the letters used to
539              designate them are: eqn (e), grap (g), pic (p), tbl (t),  vgrind
540              (v),  refer (r).  This option overrides the $MANROFFSEQ environ‐
541              ment variable.  zsoelim is always run as  the  very  first  pre‐
542              processor.
544       -t, --troff
545              Use  groff  -mandoc  to  format the manual page to stdout.  This
546              option is not required in conjunction with -H, -T, or -Z.
548       -T[device], --troff-device[=device]
549              This option is used to change groff (or possibly troff's) output
550              to  be suitable for a device other than the default.  It implies
551              -t.  Examples (provided with Groff-1.17)  include  dvi,  latin1,
552              ps, utf8, X75 and X100.
554       -H[browser], --html[=browser]
555              This  option  will  cause groff to produce HTML output, and will
556              display that output in a web browser.  The choice of browser  is
557              determined  by the optional browser argument if one is provided,
558              by the $BROWSER  environment  variable,  or  by  a  compile-time
559              default  if  that  is unset (usually lynx).  This option implies
560              -t, and will only work with GNU troff.
562       -X[dpi], --gxditview[=dpi]
563              This option displays the output of groff in a  graphical  window
564              using the gxditview program.  The dpi (dots per inch) may be 75,
565              75-12, 100, or 100-12, defaulting to 75; the -12 variants use  a
566              12-point  base  font.   This  option  implies  -T  with the X75,
567              X75-12, X100, or X100-12 device respectively.
569       -Z, --ditroff
570              groff will run troff and then use an appropriate  post-processor
571              to  produce  output  suitable  for  the chosen device.  If groff
572              -mandoc is groff, this option is passed to groff and  will  sup‐
573              press the use of a post-processor.  It implies -t.
575   Getting help
576       -?, --help
577              Print a help message and exit.
579       --usage
580              Print a short usage message and exit.
582       -V, --version
583              Display version information.


586       0      Successful program execution.
588       1      Usage, syntax or configuration file error.
590       2      Operational error.
592       3      A child process returned a non-zero exit status.
594       16     At  least one of the pages/files/keywords didn't exist or wasn't
595              matched.


598       MANPATH
599              If $MANPATH is set, its value is used as the path to search  for
600              manual pages.
602       MANROFFOPT
603              The  contents of $MANROFFOPT are added to the command line every
604              time man invokes the formatter (nroff, troff, or groff).
606       MANROFFSEQ
607              If $MANROFFSEQ is set, its value is used to determine the set of
608              preprocessors  to  pass  each  manual page through.  The default
609              preprocessor list is system dependent.
611       MANSECT
612              If $MANSECT is set, its value is a colon-delimited list of  sec‐
613              tions  and  it  is  used  to  determine which manual sections to
614              search and in what order.  The default is "1 1p 8 2 3 3p 3pm 4 5
615              6  7 9 0p n l p o 1x 2x 3x 4x 5x 6x 7x 8x", unless overridden by
616              the SECTION directive in /etc/man_db.conf.
619              If $MANPAGER or $PAGER is set ($MANPAGER is used in preference),
620              its value is used as the name of the program used to display the
621              manual page.  By default, less is used, falling back to  cat  if
622              less is not found or is not executable.
624              The  value  may be a simple command name or a command with argu‐
625              ments, and may use shell quoting (backslashes, single quotes, or
626              double  quotes).   It may not use pipes to connect multiple com‐
627              mands; if you need that, use a wrapper script,  which  may  take
628              the file to display either as an argument or on standard input.
630       MANLESS
631              If $MANLESS is set, its value will be used as the default prompt
632              string for the less pager, as if it had been passed using the -r
633              option  (so any occurrences of the text $MAN_PN will be expanded
634              in the same way).  For example, if you want to  set  the  prompt
635              string  unconditionally  to  “my prompt string”, set $MANLESS to
636-Psmy prompt string’.  Using the -r option overrides this envi‐
637              ronment variable.
639       BROWSER
640              If  $BROWSER is set, its value is a colon-delimited list of com‐
641              mands, each of which in turn is used  to  try  to  start  a  web
642              browser  for  man  --html.  In each command, %s is replaced by a
643              filename containing the HTML output from groff, %%  is  replaced
644              by a single percent sign (%), and %c is replaced by a colon (:).
646       SYSTEM If  $SYSTEM  is  set,  it will have the same effect as if it had
647              been specified as the argument to the -m option.
649       MANOPT If $MANOPT is set, it will be parsed prior to man's command line
650              and  is expected to be in a similar format.  As all of the other
651              man specific environment variables can be expressed  as  command
652              line  options,  and  are  thus  candidates for being included in
653              $MANOPT it is expected that they  will  become  obsolete.   N.B.
654              All  spaces  that  should  be interpreted as part of an option's
655              argument must be escaped.
657       MANWIDTH
658              If $MANWIDTH is set, its value is used as the  line  length  for
659              which  manual pages should be formatted.  If it is not set, man‐
660              ual pages will be formatted with a line  length  appropriate  to
661              the  current  terminal (using the value of $COLUMNS, an ioctl(2)
662              if available, or falling back to 80  characters  if  neither  is
663              available).   Cat pages will only be saved when the default for‐
664              matting can be used, that is when the terminal  line  length  is
665              between 66 and 80 characters.
668              Normally,  when output is not being directed to a terminal (such
669              as to a file or a pipe), formatting characters are discarded  to
670              make  it  easier to read the result without special tools.  How‐
671              ever, if $MAN_KEEP_FORMATTING is set  to  any  non-empty  value,
672              these  formatting  characters  are retained.  This may be useful
673              for wrappers around man that can  interpret  formatting  charac‐
674              ters.
677              Normally,  when  output is being directed to a terminal (usually
678              to a pager), any error output from the command used  to  produce
679              formatted  versions of manual pages is discarded to avoid inter‐
680              fering with the pager's display.  Programs such as  groff  often
681              produce  relatively  minor  error  messages  about typographical
682              problems such as poor alignment, which are unsightly and  gener‐
683              ally  confusing when displayed along with the manual page.  How‐
684              ever,  some  users   want   to   see   them   anyway,   so,   if
685              $MAN_KEEP_STDERR  is  set  to  any non-empty value, error output
686              will be displayed as usual.
689              Depending on system and implementation, either or both of  $LANG
690              and  $LC_MESSAGES  will  be interrogated for the current message
691              locale.  man will display its messages in that locale (if avail‐
692              able).  See setlocale(3) for precise details.


695       /etc/man_db.conf
696              man-db configuration file.
698       /usr/share/man
699              A global manual page hierarchy.
701       /usr/share/man/index.(bt|db|dir|pag)
702              A traditional global index database cache.
704       /var/cache/man/index.(bt|db|dir|pag)
705              An FHS compliant global index database cache.


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


713       1990, 1991 – Originally written by John W. Eaton (jwe@che.utexas.edu).
715       Dec 23 1992: Rik Faith (faith@cs.unc.edu) applied bug fixes supplied by
716       Willem Kasdorp (wkasdo@nikhefk.nikef.nl).
718       30th April 1994 – 23rd February 2000: Wilf. (G.Wilford@ee.surrey.ac.uk)
719       has been developing and maintaining this package with the help of a few
720       dedicated people.
722       30th  October  1996  –  30th  March  2001:   Fabrizio   Polacco   <fpo‐
723       lacco@debian.org>  maintained  and enhanced this package for the Debian
724       project, with the help of all the community.
726       31st March 2001 – present day: Colin  Watson  <cjwatson@debian.org>  is
727       now developing and maintaining man-db.
7312.8.4                             2018-07-27                            MAN(1)