man system ] string ] config_file ] pathlist ] pager ] 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\fR.\fP
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
man.config(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" .
-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 one-line 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 output from
/usr/bin/groff -Tps -mandoc 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.
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
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
man N or
cat N where
N is the manual section number.
If the file is in a
cat N 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.
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).
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