man man

NAME
       who - show who is logged on

SYNOPSIS
       who [OPTION]... [ FILE | ARG1 ARG2 ]

DESCRIPTION
       Print information about users who are currently logged in.

       -a, --all
              same as -b -d --login -p -r -t -T -u

       -b, --boot
              time of last system boot

       -d, --dead
              print dead processes

       -H, --heading
              print line of column headings

       -l, --login
              print system login processes

       --lookup
              attempt to canonicalize hostnames via DNS

       -m     only hostname and user associated with stdin

       -p, --process
              print active processes spawned by init

       -q, --count
              all login names and number of users logged on

       -r, --runlevel
              print current runlevel

       -s, --short
              print only name, line, and time (default)

       -t, --time
              print last system clock change

       -T, -w, --mesg
              add user’s message status as +, - or ?

       -u, --users
              list users logged in

       --message
              same as -T

       --writable
              same as -T

       --help display this help and exit

       --version
              output version information and exit

       If  FILE is not specified, use /var/run/utmp.  /var/log/wtmp as FILE is
       common.  If ARG1 ARG2 given, -m presumed: ‘am i’  or  ‘mom  likes’  are
       usual.

AUTHOR
       Written by Joseph Arceneaux, David MacKenzie, and Michael Stone.

REPORTING BUGS
       Report who bugs to bug-coreutils@gnu.org
       GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
       General help using GNU software: <http://www.gnu.org/gethelp/>
       Report who translation bugs to <http://translationproject.org/team/>

COPYRIGHT
       Copyright  ©  2010  Free Software Foundation, Inc.  License GPLv3+: GNU
       GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       This is free software: you are free  to  change  and  redistribute  it.
       There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
       The  full  documentation for who is maintained as a Texinfo manual.  If
       the info and who programs are properly installed at your site, the com-
       mand

              info coreutils 'who invocation'

       should give you access to the complete manual.

GNU coreutils 8.4                 March 2017                            WHO(1)
[pjc@hosts linuxc]$ man man >mannnnn.txt
[pjc@hosts linuxc]$ cat mannnnn.txt 
man(1)                                                                  man(1)

NAME
       man - format and display the on-line manual pages

SYNOPSIS
       man [-acdDfFhkKtvVwW] [--path] [-m system] [-p string] [-C config_file]
       [-M pathlist] [-P pager] [-B browser] [-H htmlpager] [-S  section_list]
       [section] name ...

DESCRIPTION
       man formats and displays the on-line manual pages.  If you specify sec-
       tion, man only looks in that section of the manual.  name  is  normally
       the  name of the manual page, which is typically the name of a command,
       function, or file.  However, if name contains  a  slash  (/)  then  man
       interprets  it  as a file specification, so that you can do man ./foo.5
       or even man /cd/foo/bar.1.gz.

       See below for a description of where man  looks  for  the  manual  page
       files.

MANUAL SECTIONS
       The standard sections of the manual include:

       1      User Commands

       2      System Calls

       3      C Library Functions

       4      Devices and Special Files

       5      File Formats and Conventions

       6      Games et. Al.

       7      Miscellanea

       8      System Administration tools and Daemons

       Distributions  customize  the  manual section to their specifics, which
       often include additional sections.

OPTIONS
       -C  config_file
              Specify   the   configuration   file  to  use;  the  default  is
              /etc/man.config.  (See man.config(5).)

       -M  path
              Specify the list of directories to search for man pages.   Sepa-
              rate  the directories with colons.  An empty list is the same as
              not specifying -M at all.  See SEARCH PATH FOR MANUAL PAGES.

       -P  pager
              Specify which pager to use.  This option overrides the  MANPAGER
              environment  variable,  which  in turn overrides the PAGER vari-
              able.  By default, man uses /usr/bin/less -is.

       -B     Specify which browser to use on HTML files.  This  option  over-
              rides  the  BROWSER  environment  variable. By default, man uses
              /usr/bin/less-is,

       -H     Specify a command that renders HTML files as text.  This  option
              overrides  the  HTMLPAGER  environment variable. By default, man
              uses /bin/cat,

       -S  section_list
              List is a colon separated list of  manual  sections  to  search.
              This option overrides the MANSECT environment variable.

       -a     By default, man will exit after displaying the first manual page
              it finds.  Using this option forces man to display all the  man-
              ual pages that match name, not just the first.

       -c     Reformat  the  source man page, even when an up-to-date cat page
              exists.  This can be meaningful if the cat  page  was  formatted
              for  a screen with a different number of columns, or if the pre-
              formatted page is corrupted.

       -d     Don’t actually display the man  pages,  but  do  print  gobs  of
              debugging information.

       -D     Both display and print debugging info.

       -f     Equivalent to whatis.

       -F or --preformat
              Format only - do not display.

       -h or --help
              Print a help message and exit.

       -v, -V or --version
              Print version information and exit.

       -k     Equivalent to apropos.

       -K     Search  for  the  specified  string in *all* man pages. Warning:
              this is probably very slow!  It  helps  to  specify  a  section.
              (Just  to  give  a  rough idea, on my machine this takes about a
              minute per 500 man pages.)

       -m  system
              Specify an alternate set of man pages to  search  based  on  the
              system name given.

       -p  string
              Specify  the  sequence  of  preprocessors to run before nroff or
              troff.  Not all installations will have a full set of preproces-
              sors.   Some of the preprocessors and the letters used to desig-
              nate them are: eqn (e), grap (g), pic (p), tbl (t), vgrind  (v),
              refer  (r).   This  option  overrides the MANROFFSEQ environment
              variable.

       -t     Use /usr/bin/groff -Tps -mandoc to format the manual page, pass-
              ing  the  output  to  stdout.   The  default  output  format  of
              /usr/bin/groff -Tps -mandoc is Postscript, refer to  the  manual
              page  of  /usr/bin/groff -Tps -mandoc for ways to pick an alter-
              nate format.

       Depending on the selected  format  and  the  availability  of  printing
       devices,  the  output  may  need  to  be  passed through some filter or
       another before being printed.

       -w or --path
              Don’t actually display the man pages, but  do  print  the  loca-
              tion(s) of the files that would be formatted or displayed. If no
              argument is given: display (on stdout) the list  of  directories
              that  is  searched by man for man pages. If manpath is a link to
              man, then "manpath" is equivalent to "man --path".

       -W     Like -w, but print file names one per line,  without  additional
              information.   This is useful in shell commands like man -aW man
              | xargs ls -l

CAT PAGES
       Man will try to save the formatted man pages, in order to save  format-
       ting time the next time these pages are needed.  Traditionally, format-
       ted versions of pages in DIR/manX are saved in DIR/catX, but other map-
       pings  from man dir to cat dir can be specified in /etc/man.config.  No
       cat pages are saved when the required cat directory does not exist.  No
       cat pages are saved when they are formatted for a line length different
       from 80.  No cat pages are saved  when  man.config  contains  the  line
       NOCACHE.

       It is possible to make man suid to a user man. Then, if a cat directory
       has owner man and mode 0755 (only writable by man), and the  cat  files
       have  owner  man  and  mode  0644 or 0444 (only writable by man, or not
       writable at all), no ordinary user can change  the  cat  pages  or  put
       other  files  in the cat directory. If man is not made suid, then a cat
       directory should have mode 0777 if all users should be  able  to  leave
       cat pages there.

       The  option  -c  forces  reformatting a page, even if a recent cat page
       exists.

HTML PAGES
       Man will find HTML pages if they live in directories named as  expected
       to  be  ".html", thus a valid name for an HTML version of the ls(1) man
       page would be /usr/share/man/htmlman1/ls.1.html.

SEARCH PATH FOR MANUAL PAGES
       man uses a sophisticated method of finding manual page files, based  on
       the  invocation  options and environment variables, the /etc/man.config
       configuration file, and some built in conventions and heuristics.

       First of all, when the name argument to man contains a slash  (/),  man
       assumes  it  is  a file specification itself, and there is no searching
       involved.

       But in the normal case where name doesn’t contain a slash, man searches
       a variety of directories for a file that could be a manual page for the
       topic named.

       If you specify the -M pathlist option, pathlist  is  a  colon-separated
       list of the directories that man searches.

       If  you  don’t specify -M but set the MANPATH environment variable, the
       value of that  variable  is  the  list  of  the  directories  that  man
       searches.

       If  you  don’t  specify  an  explicit path list with -M or MANPATH, man
       develops its own path list based on the contents of  the  configuration
       file /etc/man.config.  The MANPATH statements in the configuration file
       identify particular directories to include in the search path.

       Furthermore, the MANPATH_MAP statements add to the search path  depend-
       ing  on your command search path (i.e. your PATH environment variable).
       For each directory that may be in  the  command  search  path,  a  MAN-
       PATH_MAP  statement  specifies  a directory that should be added to the
       search path for manual page files.  man looks at the PATH variable  and
       adds the corresponding directories to the manual page file search path.
       Thus, with the proper use of MANPATH_MAP, when you  issue  the  command
       man  xyz,  you  get a manual page for the program that would run if you
       issued the command xyz.

       In addition, for each directory in the command search path (we’ll  call
       it  a  "command  directory")  for  which  you do not have a MANPATH_MAP
       statement, man automatically looks for a manual page directory "nearby"
       namely as a subdirectory in the command directory itself or in the par-
       ent directory of the command directory.

       You can disable the automatic "nearby" searches by  including  a  NOAU-
       TOPATH statement in /etc/man.config.

       In  each  directory in the search path as described above, man searches
       for a file named topic.section, with an optional suffix on the  section
       number  and  possibly  a compression suffix.  If it doesn’t find such a
       file, it then looks in any subdirectories named manN or catN where N is
       the  manual section number.  If the file is in a catN subdirectory, man
       assumes it is a formatted manual page file (cat page).  Otherwise,  man
       assumes it is unformatted.  In either case, if the filename has a known
       compression suffix (like .gz), man assumes it is gzipped.

       If you want to see where (or if) man would find the manual page  for  a
       particular topic, use the --path (-w) option.

ENVIRONMENT
       MANPATH
              If  MANPATH is set, man uses it as the path to search for manual
              page files.  It overrides the configuration file and  the  auto-
              matic  search  path,  but  is  overridden  by  the -M invocation
              option.  See SEARCH PATH FOR MANUAL PAGES.

       MANPL  If MANPL is set, its value is used as the display  page  length.
              Otherwise, the entire man page will occupy one (long) page.

       MANROFFSEQ
              If  MANROFFSEQ is set, its value is used to determine the set of
              preprocessors run before running nroff or  troff.   By  default,
              pages are passed through the tbl preprocessor before nroff.

       MANSECT
              If  MANSECT  is set, its value is used to determine which manual
              sections to search.

       MANWIDTH
              If MANWIDTH is set, its value is  used  as  the  width  manpages
              should  be displayed.  Otherwise the pages may be displayed over
              the whole width of your screen.

       MANPAGER
              If MANPAGER is set, its value is used as the name of the program
              to  use to display the man page.  If not, then PAGER is used. If
              that has no value either, /usr/bin/less -is is used.

       BROWSER
              The name of a browser to use for displaying HTML  manual  pages.
              If it is not set, /usr/bin/less -is is used.

       HTMLPAGER
              The  command to use for rendering HTML manual pages as text.  If
              it is not set, /bin/cat is used.

       LANG   If LANG is set, its value defines the name of  the  subdirectory
              where  man first looks for man pages. Thus, the command ‘LANG=dk
              man 1 foo’ will cause man to  look  for  the  foo  man  page  in
              .../dk/man1/foo.1,  and  if  it cannot find such a file, then in
              .../man1/foo.1, where ... is a directory on the search path.

       NLSPATH, LC_MESSAGES, LANG
              The environment variables NLSPATH and LC_MESSAGES (or LANG  when
              the  latter  does not exist) play a role in locating the message
              catalog.  (But the English messages are  compiled  in,  and  for
              English no catalog is required.)  Note that programs like col(1)
              called by man also use e.g. LC_CTYPE.

       PATH   PATH helps determine the search path for manual page files.  See
              SEARCH PATH FOR MANUAL PAGES.

       SYSTEM SYSTEM is used to get the default alternate system name (for use
              with the -m option).

BUGS
       The -t option only works if a troff-like program is installed.
       If you see blinking  \255  or  <AD>  instead  of  hyphens,  put  ‘LESS-
       CHARSET=latin1’ in your environment.

TIPS
       If you add the line

        (global-set-key  [(f1)]  (lambda  () (interactive) (manual-entry (cur-
       rent-word))))

       to your .emacs file, then hitting F1 will give you the man page for the
       library call at the current cursor position.

       To  get  a  plain  text  version  of a man page, without backspaces and
       underscores, try

         # man foo | col -b > foo.mantxt

AUTHOR
       John W. Eaton was the  original  author  of  man.   Zeyd  M.  Ben-Halim
       released  man  1.2,  and  Andries Brouwer followed up with versions 1.3
       thru 1.5p.  Federico  Lucifredi  <flucifredi@acm.org>  is  the  current
       maintainer.

SEE ALSO        apropos(1), whatis(1), less(1), groff(1), man.config(5).