Usage statements
Usage statements are a way to represent command syntax and consist of symbols such as brackets ([ ]), braces ({ }), and vertical bars (|).
The following is a sample of a usage statement for the unget command:
unget [ -rSID ] [ -s ] [ -n ] File ...
The following conventions are used in the command usage statements:
- Items that must be entered literally on the command line are in bold. These items include the command name, flags, and literal characters.
- Items representing variables that must be replaced by a name are in italics. These items include parameters that follow flags and parameters that the command reads, such as Files and Directories.
- Parameters enclosed in brackets are optional.
- Parameters enclosed in braces are required.
- Parameters not enclosed in either brackets or braces are required.
- A vertical bar signifies that you choose only one parameter. For example, [ a | b ] indicates that you can choose a, b, or nothing. Similarly, { a | b } indicates that you must choose either a or b.
- Ellipses (
...
) signify the parameter can be repeated on the command line. - The dash (
-
) represents standard input.