A command consists of two parts: a name and its arguments. The command name is the name used to start the command. The name is usually the name of a file which can be executed. The only exceptions are commands which are built-in to the shell. These commands are documented in the Chapter called Builtin Command Reference. Any shell utility command with a filetype of EXE, SYS16, or EXEC, can be executed in this fashion. The command name must be separated from the command arguments with a space.
The command arguments are parameters that the command takes as data to work with (In Applesoft BASIC, "HELLO WORLD" would be an argument for the PRINT command). Command arguments are separated from each other with a space. Note that although arguments extend the usefulness of a command, not all commands have arguments. Any arguments entered after the command will be passed by the shell to the program when it starts exectuting.
The examples below use the following commands:
At the simplest level the user enters commands to the shell by typing them on the keyboard. gsh includes a command-line editor to help the user enter and edit commands. The editor also provides a way to modify and execute previous commands. Additionally the editor can help complete the names of commands, filenames and variables.