How to use the command 'man' (with examples)

The ‘man’ command is used to format and display the manual pages on a Linux or Unix system. Manual pages provide documentation for various commands and functions available on the system. The ‘man’ command is particularly useful when you need to quickly look up usage and information about a specific command.

Use case 1: Display the man page for a command

Code:

man command

Motivation: You want to quickly access the manual page for a particular command to understand its usage, options, and examples.

Explanation: Replace ‘command’ with the actual command you want to view the manual page for. This will display the manual page for the specified command.

Example output: Viewing the man page for the ’ls’ command.

LS(1)                         User Commands                        LS(1)

NAME
       ls - list directory contents

SYNOPSIS
       ls [OPTION]... [FILE]...

DESCRIPTION
       List information about the FILEs (the current directory by default).

...

Use case 2: Display the man page for a command from section 7

Code:

man 7 command

Motivation: You want to view the manual page for a command from a specific section. Some commands have different sections within the manual pages, and this helps you access the appropriate section.

Explanation: Replace ‘command’ with the actual command you want to view the manual page for. The number after ‘man’ specifies the section number. In this example, ‘7’ refers to section 7 of the manual pages which typically contains miscellaneous information.

Example output: Viewing the man page for the ‘ascii’ command from section 7.

ASCII(7)                      Linux Programmer's Manual                      ASCII(7)

NAME
       ascii - ASCII character set encoded in octal, decimal, and hexadecimal

DESCRIPTION
       ASCII is an acronym for American Standard Code for Information Interchange.
       It is a code for representing 128 English characters as numbers, with each letter
...

Use case 3: List all available sections for a command

Code:

man --whatis command

Motivation: You want to know which sections of the manual pages contain information about a specific command.

Explanation: Replace ‘command’ with the actual command you want to list the available sections for. This command will display a list of all the sections in which the specified command appears in the manual pages.

Example output: Listing all available sections for the ‘grep’ command.

Grep (1) - print lines matching a pattern
Grep (3) - search a directory tree for files containing a pattern
Grep (3p) - search a directory tree for files containing a pattern

Use case 4: Display the path searched for manpages

Code:

man --path

Motivation: You want to know the search path used by the ‘man’ command to locate the manual pages.

Explanation: This command displays the path that ‘man’ uses to search for manual pages. It helps you understand the locations where the ‘man’ command looks for the documentation.

Example output: Displaying the path searched by the ‘man’ command.

/usr/local/man:/usr/share/man:/usr/man:/usr/local/share/man

Use case 5: Display the location of a manpage rather than the manpage itself

Code:

man --where command

Motivation: You want to find the exact location of a specific manpage without displaying its contents.

Explanation: Replace ‘command’ with the actual command you want to find the location of. This command will display the path of the specified command’s manual page without opening the manual page itself.

Example output: Finding the location of the ’tar’ command’s manual page.

/usr/share/man/man1/tar.1.gz

Use case 6: Display the man page using a specific locale

Code:

man --locale=locale command

Motivation: You want to view the manual page using a specific locale to ensure the content is displayed correctly for your language and region.

Explanation: Replace ’locale’ with the desired locale for viewing the manual page, and replace ‘command’ with the actual command you want to view the manual page for. This command allows you to specify a locale to use when formatting and displaying the manual page.

Example output: Viewing the ‘chmod’ command’s manual page in French locale.

CHMOD(1)                  Manuel de l'utilisateur de Linux                  CHMOD(1)

NOM
       chmod - modifier les droits d'accès aux fichiers

SYNOPSIS
       chmod [OPTION]... MODE[,MODE]... FICHIER...
...

Use case 7: Search for manpages containing a search string

Code:

man --apropos "search_string"

Motivation: You want to search for keywords or topics within the manual pages to find relevant command documentation.

Explanation: Replace ‘search_string’ with the specific term or keyword you want to search for. This command will display a list of manual pages that contain the specified search string.

Example output: Searching for manual pages containing the term ‘filesystem’.

dumpe2fs (8)        - dump ext2/ext3/ext4 filesystem information
mount (8)           - mount a filesystem
mount.cifs (8)      - mount using the Common Internet File System (CIFS)
umount (8)          - unmount file systems
unshare (1)         - run program with some namespaces unshared from the parent

Conclusion:

The ‘man’ command is a powerful tool for accessing and viewing the manual pages of various commands and functions on a Linux or Unix system. It allows you to quickly find information, usage, and examples for specific commands, as well as navigate through different sections and search for relevant topics or keywords. Understanding these different use cases of the ‘man’ command can greatly enhance your efficiency and productivity when working on the command line.