Help Facts

Man Interface

  • Man Pages: Text-based help files for commands, services, or configuration files in Linux.

    • Open with man [command] or le [command].

    • Use man -k [search term] to find commands related to a term.

  • Storage Locations:

    • Typically in /usr/man or /usr/share/man.

    • Some distributions use the MANPATH environment variable to define locations.

    • View it with echo $MANPATH.

    • Configuration can be found in /etc/man_db.conf or /etc/manpath.config.

Man Page Structure

  • TITLE: First line with command name and section number.

  • NAME: Command name and brief description.

  • SYNOPSIS: Command syntax overview.

  • DESCRIPTION: Details on how the command works.

  • OPTIONS: List of available options for the command.

  • AUTHOR: Programmer's name.

  • REPORTING BUGS: Contact for bug reports.

  • COPYRIGHT: Ownership information.

  • SEE ALSO: Related man pages/resources.

  • VERSION: Last line showing version number and revision date.

Navigation in Man Pages

  • Use arrow keys, PgUp, and PgDn to navigate.

  • q to exit the man page.

  • Use / to search for specific text within a page.

    • n to jump to next occurrence.

Info Reader

  • Open with info [command].

  • Navigated using: Up/Down arrows, PgUp, PgDn, Home, End, and q to exit.

  • Similar to man pages but more verbose with emphasis on usage.

On-Screen Help and the Help Command

  • Many commands provide on-screen help via options like --help.

  • Abbreviated list showing command syntax and available options.

    • Example: jobs --help

  • Common Help Command Options:

    • -d: Short description for each topic.

    • -m: Command usage in pseudo-man format.

    • -s: Short usage synopsis.

/usr/share/doc Directory

  • Contains documentation resources for Linux components.

  • Typical files: NEWS, README, AUTHOR, OVERVIEW, COPYING.

  • Use cat to view file contents.

Whatis Database

  • Use whatis [keyword] for one-line command descriptions.

    • Example: whatis grep

  • Apropos Command: Use apropos [keyword] to find related commands.

    • Both commands utilize the whatis database.

  • To update or create the whatis database, use /usr/sbin/makewhatis.