Task: Look Up Information on a Topic
To look up info on a topic, type info topic, for example:
$ info ls
To invoke a man page about a command or system file, type man command at the shell prompt. For example, to get help on the command ls, type
$ man ls
The manual page for that command opens, as shown in Figure 3.5. The first line of the man page is the name of the command, a synopsis of all the different switches and parameters that you can attach to the command, and a detailed description of the command usage.
To scroll through the man page, use the arrow down and arrow up buttons.
To quit the man page, enter q.
In addition to the man and info pages, many commands come with an option that prints out a description of the command, such as command --help. Also, all the documentation that comes with application packages that you install is stored in /usr/doc. Many of the files are simple README files or other notes, but you can sometimes find a wealth of information (the X documents are an example).