Gentoo Man Guide
The man program
Everyone at some point in their linux life has used it. "It" is the man
command. However, while the man program itself appears to be rather simplistic
in its construct, it has a few extra abilities than just simply scrolling
through the page. This document hopes to help shed some light on these
Man pages are mainly stored in the /usr/share/man directory.
However, as long as a man page is located in the MANPATH environment
variable, man will be able to pick it up. Gentoo will generally store
MANPATH variables in /etc/env.d. Within these directories
are some folders with the structure manX where X is the section number. For
example, a standard man layout might look like so:
Code Listing 1.1: Standard man structure
$ ls /usr/share/man | grep man
The actual section numbering appears fairly standard. However, notice that
there is a mann and some man#p folders. The following
table lists the above man page directories and what is contained within them:
The p here stands for POSIX, as with the other directories with p in
their names. Man pages in this directory describe the functionality of
various POSIX header files.
This section is for standard commands. Most programs will put their man
pages here, so this section tends to be the largest.
This section describes the POSIX versions of the commands described in 1p.
Since it only describes basic commands, it is much smaller than man1.
||This section describes Linux kernel system calls.
||This section describes standard c library functions.
This section describes special devices. These devices are generally kernel
oriented, but Xorg-X11 has entries in here as well.
This section describes both the makeup of certain files and what files a
program uses. Those of you reading this document may be familiar with
references to man 5 portage for a description of the portage
file structure, and man 5 make.conf for make.conf
||This section introduces games and other special toys.
This section describes standards and other miscellaneous items. These
standards can include things such as charsets, SQL statements, ISO
standards and regular expressions.
This section describes administrative commands (those usually run by the
This section is somewhat sparse, but is meant to contain documentation for
various parts of the kernel.
This section is mainly used by Tcl/Tk. The n stands for new.
While this is not an extensive and detailed list, it does cover the man pages
that most people will be interested in. However, sometimes you can find out
what a section does as easily as looking at this table. The next chapter will
look at using man to traverse this layout.
Working with the man layout
Browsing the man layout
Now that we understand the man layout, we can begin to look it over for
commands. Sometimes we may need to narrow down what man page we want. The first
way would be addressing by section. To found out a description of a section,
once can use man section intro like so:
Code Listing 2.1: Using man intro to describe a section
$ man 3 intro
INTRO(3) Linux Programmer's Manual INTRO(3)
intro - Introduction to library functions
This chapter describes all library functions excluding the library
functions described in chapter 2, which implement system calls.
There are various function groups which can be identified by a
letter which is appended to the chapter number:
Unfortunately, this doesn't always work! However, luckily for us there is
another way to search for commands that may return multiple results (such as a
library call and system command having the same name). To do so, we use the
-K parameter to man like so:
Code Listing 2.2: Using man -K to search by string
$ man -K sleep
/usr/share/man/man0p/time.h.0p.gz? [ynq] n
/usr/share/man/man0p/unistd.h.0p.gz? [ynq] n
/usr/share/man/man2/alarm.2.gz? [ynq] n
/usr/share/man/man2/pause.2.gz? [ynq] n
/usr/share/man/man2/futex.2.gz? [ynq] n
/usr/share/man/man2/nanosleep.2.gz? [ynq] y
/usr/share/man/man2/semop.2.gz? [ynq] q
Sometimes the output may be a lot larger. In this case it might be better to
specify more specific keywords. Now that we know where to find the man page,
the next section will look at viewing the man page.
Viewing man pages
Viewing man pages can be done in 2 ways, first is with man [man page
name]. The second way is man [section] [man page name]. Let's take
bc for example. I can view either the first man page that comes up on
bc (which would be section 1, because it is the lowest section
containing a man page on bc):
Code Listing 2.3: Viewing the default man page
$ man bc
bc - An arbitrary precision calculator language
However, what if I want the POSIX version? Then I can use the second form:
Code Listing 2.4: Viewing a specific man page by section
$ man 1p bc
BC(P) POSIX Programmer's Manual BC(P)
bc - arbitrary-precision arithmetic language
And the man page is displayed. Now that we have the man page up, it's time to
work with it. The next section will look at navigation and searching.
Navigating and searching man pages
Navigating a man page is fairly simple. To move up and down line by line, use
the up and down arrow keys. To move up page by page, you can use the page up
and page down keys. Do however note that these navigation instructions assume
the environmental PAGER variable is set to use the default pager,
less. Less also has a few other commands for navigation, but the arrow
keys usually suffice:
Code Listing 2.5: Additional less navigation keys
e ^E j ^N CR * Forward one line (or N lines).
y ^Y k ^K ^P * Backward one line (or N lines).
f ^F ^V SPACE * Forward one window (or N lines).
b ^B ESC-v * Backward one window (or N lines).
z * Forward one window (and set window to N).
w * Backward one window (and set window to N).
ESC-SPACE * Forward one window, but don't stop at end-of-file.
d ^D * Forward one half-window (and set half-window to N).
u ^U * Backward one half-window (and set half-window to N).
ESC-) RightArrow * Left one half screen width (or N positions).
ESC-( LeftArrow * Right one half screen width (or N positions).
F Forward forever; like "tail -f".
Searching, however, is more interesting. The two most basic searches are
/pattern and ?pattern. The first version searches forwards, and
the second searches backwards. pattern is a regular expression pattern
that is described in man 7 regex. Let's take for example searching for
the -D option to emerge. First, bring up the emerge man page:
Code Listing 2.6: Bringing up the emerge man page
$ man emerge
Then, at the screen, press the / key to bring up the entry prompt to
search forwards and enter in our search pattern:
Code Listing 2.7: Bringing up the forward search prompt
gracefully handles updating installed packages to newer releases as well.
It handles both source and binary packages, and it can be used to create
binary packages for distribution.
EBUILDS, TBZ2S, CLASSES AND DEPENDENCIES
The \ is done to escape the - sign, which would normally be used
as part of a regular expression.
This will search the man page, and bring the searched item into focus:
Code Listing 2.8: Forward search results
When used in conjunction with --update, this flag forces emerge to consider the entire
dependency tree of packages, instead of checking only the immediate dependencies of
the packages. As an example, this catches updates in libraries that are not directly
listed in the dependencies of a package.
If you hit a search result by accident and want to continue searching for the
same results, simply press the / key again, and press enter (i.e. don't
put a pattern it). This will cause the search to default to the last pattern
used. Now with some man pages, options are listed, then explained later on.
Take the man 5 portage man page. It lists the files used, then explains
their usage. Searching forward a few times would return the results, but
there's an easier way to handle this, with the second search form, backwards
searching. Let's use this to find the description on
package.unmask. First, bring up man 5 portage:
Code Listing 2.9: Bringing up the man 5 portage man page
$ man 5 portage
Now press SHIFT+g. This will bring you to the end of the page:
Code Listing 2.10: End of the man page after SHIFT+g
emerge(1), ebuild(1), ebuild(5), make.conf(5)
Portage 2.0.51 Jan 2004 PORTAGE(5)
lines 418-442/442 (END)
Now we'll go ahead and enter the pattern to search for with the ?pattern
backwards search option. First press the ? key to bring up the prompt,
and then enter in package.unmask, our query:
Code Listing 2.11: Specifying our search
emerge(1), ebuild(1), ebuild(5), make.conf(5)
Portage 2.0.51 Jan 2004 PORTAGE(5)
Then hit enter to bring up the result:
Code Listing 2.12: Our search result
Just like package.mask above, except here you list packages you want to unmask.
Useful for overriding the global package.mask file (see below). Note that
this does not override packages that are masked via KEYWORDS.
And the search is complete! Note that just as with /, using ?
search with no pattern will use the last pattern to search.
This concludes the man guide. This will hopefully shed some light on navigating
man pages, and maybe even give a few new tips to the more experienced users.
For those who prefer alternate means of navigating man pages, the following are
- app-text/man2html - a program for converting man pages to html
- app-text/tkman - a tk based man page browser
Also the KDE web browser Konqueror can browse man pages using the
man: syntax in the address bar.
The contents of this document, unless otherwise expressly stated, are licensed under the CC-BY-SA-2.5 license. The Gentoo Name and Logo Usage Guidelines apply.