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UNIX manual

Almost all substantial UNIX and Unix-like operating systems have extensive documentation available as an electronic manual, split into multiple sections.

To read a page from the manual, one can use the command

$ man [


at a shell prompt, e.g. "man ftp" (the section number can usually be omitted). Pages are traditionally referred to using the notation "page_name(section)", e.g. ftp(1).

The section number is used to allow a specific manual page to be chosen when there are multiple manual pages with the same name. This can occur when the names of system calls, user commands, or macro packages conflict. Two examples are man(1) and man(7), or exit(1) and exit(3).

Manual sections

The manual is generally split into eight numbered sections, organised as follows:

Section Description
1 General commands
2 Low-level system calls
3 C library functions
4 Special files (usually devices, those found in /dev)
5 File formats and conventions
6 Gamess
7 Miscellanea
8 System administration and associated commands

On some systems some of three other sections are available:

Section Description
9 Kernel routines (obsolete)
n Tcl/Tk keywords
x The X Window System

The manual pages are stored as nroff source files. Most versions of man cache the formatted versions of the last several pages viewed.

For an example of a man page see chmod.

External links

This article was originally based on material from FOLDOC, used with permission. Update as needed.