This command is used to view the on-line reference manual pages for commands/programs.

No Option: It displays the whole manual of the command.

Example: 

$ man printf

Section-num: Since a manual is divided into multiple sections so this option is used to display only a specific section of a manual.

Example:

$ man 2 intro

-f option: One may not be able to remember the sections in which a command is present. So this option gives the section in which the given command is present.

Example:

$ man -f ls

-a option: This option helps us to display all the available intro manual pages in succession.

-k option: This option searches the given command as a regular expression in all the manuals and it returns the manual pages with the section number in which it is found.

-w option: This option returns the location in which the manual page of a given command is present.

Example:

$ man -w ls

-I option: It considers the command as case sensitive.

Format the manual page for bash into the default troff or groff format and pipe it to the printer named ps. The default output for groff is usually PostScript. man --help should advise as to which processor is bound to the -t option.

This command will decompress and format the nroff source manual page ./foo.1x.gz into a device independent (dvi) file. The redirection is necessary as the -T flag causes output to be directed to stdout with no pager. The output could be viewed with a program such as xdvi or further processed into PostScript using a program such as dvips.

Lookup the manual pages referenced by smail and print out the short descriptions of any found. Equivalent to whatis smail.