Running help commands

Traditionally, all Unix programs are documented with manual pages, available through the man command. Manual pages are used to describe commands. For example, the command man echo will display the manual page for the echo command. You can press h key while viewing a manual page. This will display a help page for movement commands in manual page. Press q key when done with help page and to quit manual page. A manual page consists of several sections. Conventional section names include NAME, SYNOPSIS, CONFIGURATION, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT, FILES, VERSIONS, CONFORMING TO, NOTES, BUGS, EXAMPLE, AUTHORS, and SEE ALSO. The SYNOPSIS section provides an example of how to use the command. In order to search a manual page, press the / key and type the term followed by the Enter key. The program will search from the current location down towards the bottom of the page to try to locate and highlight the term. If a match is found and you want to move to the next match of the term, press n key. To return to a previous match of the term, press N key. In some cases you will need to specify the section in order to display the correct manual page. This is necessary because sometimes there will be manual pages with the same name in different sections. To display a manual page for a different section, provide the section number as the first argument to the man command. For example, the following command will look for the manual page in section 5:

$ man 5 command

You can search for a manual page by name.

$ man -f command

In cases you don't remember the exact name of the manual page that you want to view.

$ man -k command

Many GNU software is documented through info pages instead of manual pages. These files include detailed information of the program itself, options and example usage and are available through the info command. Many users find info pages to be easier to read. Within info pages, information is broken down into categories that work much like a table of contents that you would find in a book. To display the info pages for a command, execute:

$ info command

First line provides information that tells you where you are. Documentation is broken up into nodes (like chapters in a book). Press H key for help to see a list of movement commands and H key again to close help window. Press q key to quit info page.

The README files are also common. They are simple text files that describe a single item, usually a package. You can find a lot of these in the /usr/share/doc/ subdirectories on your system. Each software package has a subdirectory under it with its own read me files, and might also include configuration examples.

An easy way to search for a file is to use the locate command. For example, you can find the location of file by executing the locate command.