February 2004
Beginner
200 pages
5h 40m
English
When we describe a command, we first present its general usage information. For example, the wc (word count) program has the general usage:
wc [options] [files]
which means you’d type “wc” followed, if you choose, by options and then filenames. You wouldn’t type the square brackets “[” and “]”: they just indicate their contents are optional; and words in italics mean you have to fill in your own specific values, like names of actual files. If you see a vertical bar between options or arguments, perhaps grouped by parentheses:
ls (file|directory)
this indicates choice: when running the ls command, you may supply either a file or directory name as an argument.