Guide to Eos and Unity Computing Unix Command Options and Arguments Commands tell the system what actions to perform. However, if the user wants to modify those actions and specify that the action be performed in a particular way on a certain file, then the user must add that information to the command as options and arguments . For example, all of the Unix directory commands in the previous chapter specified and affected a directory file, which was the argument in the command syntax. It is also common to add options after a command.
Options are generally single characters or a whole word preceded by a hyphen.
The option specifies a variation in the basic command, telling it to do something in a specific way. A full command consists of a command, followed by zero or more options, followed by zero or more arguments. For example, if you type the command ls to list the files in a directory, the system will display a multi-column list of file and subdirectory names only. Additional options and arguments can be added on.