man
SYNOPSIS
man [-c|-w|-tZHT device] [-adhu7V] [-i|-I] [-m sys
tem[,...]] [-L locale] [-p string] [-M path] [-P pager]
[-r prompt] [-S list] [-e extension] [[section]
page ...] ...
man -l [-7] [-tZHT device] [-p string] [-P pager] [-r
prompt] file ...
man -k [apropos options] regexp ...
man -f [whatis options] page ...
DESCRIPTION
man is the system's manual pager. Each page argument given
to man is normally the name of a program, utility or func
tion. The manual page associated with each of these argu
ments is then found and displayed. A section, if provided,
will direct man to look only in that section of the man
ual. The default action is to search in all of the avail
able sections, following a pre-defined order 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 eg /etc/passwd
6 Games
7 Miscellaneous (including macro packages and conven
tions), 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 parts.
They may be labelled NAME, SYNOPSIS, DESCRIPTION, OPTIONS,
FILES, SEE ALSO, BUGS, and AUTHOR.
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.
The command or function illustration is a pattern that
should match all possible invocations. In some cases it
Format the manual page referenced by `alias', usually
a shell manual page, 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 indepen
dent (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 dvips.
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 -r printf.
man -f smail
Lookup the manual pages referenced by smail and print
out the short descriptions of any found. Equivalent
to whatis -r smail.
OVERVIEW
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 back
slash). 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.
The manual pager utilities packaged as man-db make exten
sive use of index database caches. These caches contain
information such as where each manual page can be found on
the filesystem and what its whatis (short one line
description of the man page) contains, and allow man to
run faster than if it had to search the filesystem each
time to find the appropriate manual page. If requested
information must be known at compile time. Also, by
default, any cat pages produced are compressed using gzip.
Each `global' manual page hierarchy such as /usr/share/man
or /usr/X11R6/man may have any directory as its cat page
hierarchy. Traditionally the cat pages are stored under
the same hierarchy as the man pages, but for reasons such
as those specified in the File Hierarchy Standard (FHS),
it may be better to store them elsewhere. For details on
how to do this, please read manpath(5). For details on
why to do this, read the standard.
International support is available with this package.
Native language manual pages are accessible (if available
on your system) via use of locale functions. To activate
such support, it is necessary to set either $LC_MESSAGES,
$LANG or another system dependent environment variable to
your language locale, usually specified in the POSIX
1003.1 based format:
<language>[_<territory>[.<character-set>[,<version>]]]
If the desired page is available in your locale, it will
be displayed in lieu of the standard (usually American
English) page.
Support for international message catalogues is also fea
tured in this package and can be activated in the same
way, again if available. If you find that the manual
pages and message catalogues 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.
For information regarding other features and extensions
available with this manual pager, please read the docu
ments supplied with the package.
DEFAULTS
man will search for the desired manual pages within the
index database caches. If the -u option is given, a cache
consistency check is performed to ensure the databases
accurately reflect the filesystem. If this option is
always given, it is not generally necessary to run mandb
after the caches are initially created, unless a cache
becomes corrupt. However, the cache consistency check can
be slow on systems with many manual pages installed, so it
is not performed by default, and system administrators may
wish to run mandb every week or so to keep the database
caches fresh. To forestall problems caused by outdated
caches, man will fall back to file globbing if a cache
lookup fails, just as it would if no cache was present.
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 con
tain 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 informa
tion, a default set is used.
A formatting pipeline is formed from the filters and the
primary formatter (nroff or [tg]roff with -t) and exe
cuted. 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 speci
fied with -T or -E as arguments.
OPTIONS
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.
-l, --local-file
Activate `local' mode. Format and display local
manual files instead of searching through the sys
tem'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.
-L locale, --locale=locale
man will normally determine your current locale by
a call to the C function setlocale(3) which inter
rogates 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
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.
-P pager, --pager=pager
Specify which output pager to use. By default, man
uses exec /usr/bin/less -s. This option overrides
the $PAGER environment variable and is not used in
conjunction with -f or -k.
-r prompt, --prompt=prompt
If a recent version of less is used as the pager,
man will attempt to set its prompt and some sensi
ble 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 variable.
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\\%..
It is broken into two 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 pre
ceding 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.
If you want to override man's prompt string pro
cessing completely, use the $MANLESS environment
variable described below.
-7, --ascii
When viewing a pure ascii(7) manual page on a 7 bit
If the latin1 column displays correctly, your ter
minal 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.
-S list, --sections=list
List is a colon-separated list of `order specific'
manual sections to search. This option overrides
the $MANSECT environment variable.
-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.
-c, --catman
This option is not for general use and should only
be used by the catman program.
-d, --debug
Don't actually display any manual pages, but do
print lots of debugging information.
-e sub-extension, --extension=sub-extension
Some systems incorporate large packages of manual
pages, such as those that accompany the Tcl pack
age, 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 situa
tion and to avoid having to know which section the
page you require resides in, it is now possible to
give man a 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.
-k, --apropos
Equivalent to apropos. Search the short manual
page descriptions for keywords and display any
matches. See apropos(1) for details.
-m system[,...], --systems=system[,...]
If this system has access to other operating sys
tem'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.
-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 pre
processors and the letters used to designate them
are: eqn (e), grap (g), pic (p), tbl (t), vgrind
(v), refer (r). This option overrides the $MAN
ROFFSEQ environment variable. zsoelim is always
run as the very first preprocessor.
-u, --update
This option causes man to perform an `inode level'
consistency check on its database caches to ensure
that they are an accurate representation of the
filesystem. It will only have a useful effect if
man is installed with the setuid bit set.
-t, --troff
Use /usr/bin/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 (pro
vided with Groff-1.17) include dvi, latin1, ps,
utf8, X75 and X100.
-Z, --ditroff
groff will run troff and then use an appropriate
post-processor to produce output suitable for the
chosen device. If /usr/bin/groff -mandoc is groff,
designed, the argument to this function must be an
nroff device such as ascii, latin1, or utf8.
-w, --where, --location
Don't actually display the manual pages, but do
print the location(s) of the source nroff files
that would be formatted.
-W, --where-cat, --location-cat
Don't actually display the manual pages, but do
print the location(s) of the cat files that would
be displayed. If -w and -W are both specified,
print both separated by a space.
-V, --version
Display version information.
EXIT STATUS
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.
ENVIRONMENT
MANPATH
If $MANPATH is set, its value is used as the path
to search for manual pages.
MANROFFSEQ
If $MANROFFSEQ is set, its value is used to deter
mine the set of preprocessors to pass each manual
page through. The default preprocessor list is
system dependent.
MANSECT
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.
PAGER If $PAGER is set, its value is used as the name of
the program used to display the manual page. By
default, exec /usr/bin/less -s is used.
MANLESS
If $MANLESS is set, man will not perform any of its
usual processing to set up a prompt string for the
SYSTEM If $SYSTEM is set, it will have the same effect as
option -m string where string will be taken as
$SYSTEM's contents.
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 environ
ment 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 inter
preted as part of an option's argument must be
escaped.
MANWIDTH
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 ter
minal (using an ioctl(2) if available, the value of
$COLUMNS, or falling back to 80 characters if nei
ther 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.
LANG, LC_MESSAGES
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.
FILES
/etc/manpath.config
man-db configuration file.
/usr/share/man
A global manual page hierarchy.
/usr/share/man/index.(bt|db|dir|pag)
A traditional global index database cache.
/var/cache/man/index.(bt|db|dir|pag)
An alternate or FHS compliant global index database
cache.
SEE ALSO
mandb(8), manpath(1), manpath(5), apropos(1), whatis(1),
catman(8), less(1), nroff(1), troff(1), groff(1), zsoe
lim(1), setlocale(3), man(7), ascii(7), latin1(7), the
30th October 1996 - 30th March 2001: Fabrizio Polacco
<fpolacco@debian.org> maintained and enhanced this package
for the Debian project, with the help of all the commu
nity.
31st March 2001 - 07 September 2001: Colin Watson <cjwat
son@debian.org> is now developing and maintaining man-db.
2.4.1 07 September 2001 man(1)
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