A file with .man extension stands for man page which is a Unix programming user’s manual in software documentation form. It is used by the Man utility, included in Unix, that is used to view the documentation. The software documentation contains information in sections and pages that can be retrieved using the Man utility from command terminal by issuing commands. Being available in the computer as soft copy of documentation, it doesn’t require any printed copy or internet connection to access it.
Unix Manual Man File Format - More Information
Man pages are stored in plain text format and can be created and opened in any text editor for viewing or editing. In UNIX, information from the Man pages is retrieved by issuing commands from terminal that includes reference to section and page numbers from the manual.
Sections and Pages
Unix man is the system’s manual where each page argument to the command refers to the name of a program, utility or function. the command, if provided with section information, will search for the page in that specific section. However, the default behaviour is to search for the page in all sections and display the first page irrespective of if it exists in multiple sections.
Following is the information about the section numbers of the manual followed by the types of pages they contain.
Type of pages
Executable programs or shell commands
System calls (functions provided by the kernel)
Library calls (functions within program libraries)
Special files (usually found in /dev)
File formats and conventions, e.g. /etc/passwd
Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7)
System administration commands (usually only for root)
Kernel routines [Non standard]
Example - How to Read MAN Pages?
Here is an example how to retrieve informatino about MkDir command using the Man command.
% man mkdir
MKDIR(1) USER COMMANDS MKDIR(1)
mkdir - make a directory
mkdir [ -p ] dirname...
mkdir creates directories. Standard entries,`.',for the
directory itself, and `..' for its parent, are made automat-
The -p flag allows missing parent directories
to be created as needed.
With the exception of the set-gid bit, the
current umask(2V) setting determines the mode in which
directories are created. The new directory inherits the set-gid
bit of the parent directory. Modes may be modified after
creation by using chmod(1V).
mkdir requires write permission in the parent directory.
chmod(1V), rm(1), mkdir(2v), umask(2V)