“MAN PAGE” - -KINGDOM OF JOGA-

-as of [30 SEPTEMBER 2024]-

(short for ‘manual page’)

-a ‘man page’ is a form of ‘software documentation’ usually found on a unix (or ‘Unix-like’) operating system–

Topics covered include

computer programs (including library and system calls),

formal standards and conventions,

and even abstract concepts.

A user may invoke a man page by issuing the man command.

By default, man typically uses a terminal pager program such as more or less to display its output.

Man-pages are often referred to as an on-line or online form of software documentation,[1] even though the man command does not require internet access, dating back to the times when printed out-of-band manuals were the norm

History

xman, an early X11 application for viewing manual pages

OpenBSD section 8 intro manpage, displaying in a text console

In the first two years of the history of Unix, no documentation existed

The Unix Programmer’s Manual was first published on November 3, 1971.

The first actual man pages were written by Dennis Ritchie and Ken Thompson at the insistence[citation needed] of their manager Doug McIlroy in 1971.

Aside from the man pages, the Programmer’s Manual also accumulated a set of short papers,

some of them tutorials

(e.g. for general Unix usage, the C programming language, and tools such as Yacc),

and others more detailed descriptions of operating system features.

The printed version of the manual initially fit into a single binder, but as of PWB/UNIX and the 7th Edition of Research Unix, it was split into two volumes with the printed man pages forming Volume 1

Later versions of the documentation imitated the first man pages’ terseness.

Ritchie added a “How to get started” section to the Third Edition introduction,

and Lorinda Cherry provided the “Purple Card” pocket reference for the Sixth and Seventh Editions.[2]

Versions of the software were named after the revision of the manual;

the seventh edition of the Unix Programmer’s Manual, for example, came with the 7th Edition or Version 7 of Unix

For the Fourth Edition the man pages were formatted using the troff typesetting package[2] and its set of -man macros (which were completely revised between the Sixth and Seventh Editions of the Manual,[3] but have since not drastically changed).

At the time, the availability of online documentation through the manual page system was regarded as a great advance.

To this day, virtually every Unix command line application comes with a man page, and many Unix users perceive a program’s lack of man pages as a sign of low quality;

indeed, some projects, such as Debian, go out of their way to write man pages for programs lacking one.

The modern descendants of 4.4BSD also distribute man pages as one of the primary forms of system documentation

(having replaced the old -man macros with the newer -mdoc).

There was a hidden easter egg in the man-db version of the man command that would cause the command to return “gimme gimme gimme” when run at 00:30

(a reference to the ABBA song Gimme! Gimme! Gimme! (A Man After Midnight)

(ha!)

It was introduced in 2011[5] but first restricted[6] and then removed in 2017[7] after finally being found

Formatting

Part of the FreeBSD

man(1) manual page, typeset into PDF format.

The default format of the man pages is troff, with either the macro package man (appearance oriented) or mdoc (semantic oriented).

This makes it possible to typeset a man page into PostScript, PDF, and various other formats for viewing or printing.

Some Unix systems have a package for the man2html command, which enables users to browse their man pages using an HTML browser.

Systems with groff and man-db should use the higher-quality native HTML output (man –html) instead.

The GNU Emacs program WoMan (from “WithOut man”) allows to browse man pages from the editor.[9]

In 2010, OpenBSD deprecated troff for formatting manpages in favour of mandoc, a specialised compiler/formatter for manpages with native support for output in PostScript, HTML, XHTML, and the terminal.

It is meant to only support of a subset of troff used in manual pages, specifically those using the mdoc macros

Online services

Quite a few websites offer online access for manual pages from various Unix-like systems.

In February 2013, the BSD community saw a new open source mdoc.su service launched, which unified and shortened access to the man.cgi scripts of the major modern BSD projects through a unique nginx-based deterministic URL shortening service for the *BSD man pages

For Linux, a man7.org service has been set up to serve manuals specific to the system.

A ManKier service provides a wider selection, and integrates the TLDR pages too

Command usage

To read a manual page for a Unix command, a user can type:

Pages are traditionally referred to using the notation “name(section)”: for example, ftp(1).

The section refers to different ways the topic might be referenced –

for example, as a system call, or a shell (command line) command or package, or a package’s configuration file, or as a coding construct / header.

The same page name may appear in more than one section of the manual, such as when the names of system calls, user commands, or macro packages coincide.

Examples are man(1) and man(7), or exit(2) and exit(3).

The syntax for accessing the non-default manual section varies between different man implementations.

On Solaris and illumos, for example, the syntax for reading printf(3C) is:

On Linux and BSD derivatives the same invocation would be:

which searches for printf in section 3 of the man pages

Manual sections

The manual is generally split into eight numbered sections, organized as follows (on Research Unix, BSD, macOS and Linux)

Section Description

1 General commands

2 System calls

3 Library functions, covering in particular the C standard library

4 Special files (usually devices, those found in /dev) and drivers

5 File formats and conventions

6 Games and screensavers

7 Miscellanea

8 System administration commands and daemons

POSIX system calls are often present in both sections 2 and 3, where section 2 contains the system call’s documentation from the local operating system and section 3 contains the system call’s documentation from the POSIX Programmer’s Manual.[citation needed]

Unix System V uses a similar numbering scheme, except in a different order:[19]

Section Description

1 General commands

1M System administration commands and daemons

2 System calls

3 C library functions

4 File formats and conventions

5 Miscellanea

6 Games and screensavers

7 Special files (usually devices, those found in /dev) and drivers

On some systems some of the following sections are available:

Section Description

0 C library header files (Unix v6)

9 Kernel routines (FreeBSD, SVR4, Linux)[18][16]

n Tcl/Tk commands

x The X Window System

Some sections are further subdivided by means of a suffix;

for example, in some systems, section 3C is for C library calls, 3M is for the math library, and so on.

A consequence of this is that section 8 (system administration commands) is sometimes relegated to the 1M subsection of the main commands section

Some subsection suffixes have a general meaning across sections:

Subsection Description

p POSIX specifications

x X Window System documentation

(Section 3 tends to be the exception with the many suffixes for different languages.)

Some versions of man cache the formatted versions of the last several pages viewed.

One form is the cat page, simply piped to the pager for display

Layout

All man pages follow a common layout that is optimized for presentation on a simple ASCII text display, possibly without any form of highlighting or font control.

Sections present may include:[20](MANUAL STRUCTURE)

NAME

The name of the command or function, followed by a one-line description of what it does.

SYNOPSIS

In the case of a command, a formal description of how to run it and what command line options it takes. For program functions, a list of the parameters the function takes and which header file contains its declaration.

DESCRIPTION

A textual description of the functioning of the command or function.

EXAMPLES

Some examples of common usage.