NAME
man - format and display the on-line manual pages
SYNOPSIS
man [-acdfFhkKtwW] [--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 section, 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.
OPTIONS
- -C config_file
- Specify the configuration file to use; the default is
/etc/man.config. (See (5).)
- -M path
- Specify the list of directories to search for man pages.
Separate 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 variable. By default, man uses /usr/bin/less
-is.
- -B
- Specify which browser to use on HTML files. This option
overrides 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 manual 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 preformatted
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
- Print a help message 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 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.
- -t
- Use /usr/bin/groff -Tps -mandoc to format the manual
page, passing 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 alternate 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
location(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 formatting time the next time these pages are needed.
Traditionally, formatted versions of pages in DIR/manX are saved in
DIR/catX, but other mappings 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 depending on your command search path (i.e. your PATH
environment variable). For each directory that may be in the
command search path, a MANPATH_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 parent directory of the
command directory.
You can disable the automatic "nearby" searches by including a
NOAUTOPATH 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 automatic 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
`LESSCHARSET=latin1' in your environment.
TIPS
If you add the line
(global-set-key [(f1)] (lambda () (interactive) (manual-entry (current-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).