Shell features
There are advantages to using the shell as an interface to the system.
The primary advantages of interfacing to the system through a shell are as follows:
- Wildcard substitution in file names (pattern-matching)
Carries out commands on a group of files by specifying a pattern to match, rather than specifying an actual file name.
For more information, see:
- Background processing
Sets up lengthy tasks to run in the background, freeing the terminal for concurrent interactive processing.
For more information, see the bg command in the following:
- Job control in the Korn shell or POSIX shell
- C shell built-in commands Note: The Bourne shell does not support job control.
- Command aliasing
Gives an alias name to a command or phrase. When the shell encounters an alias on the command line or in a shell script, it substitutes the text to which the alias refers.
For more information, see:
- Command aliasing in the Korn shell or POSIX shell
- Alias substitution in the C shell Note: The Bourne shell does not support command aliasing.
- Command history
Records the commands you enter in a history file. You can use this file to easily access, modify, and reissue any listed command.
For more information, see the history command in the following:
- Korn shell or POSIX shell command history
- C shell built-in commands
- History substitution in the C shell Note: The Bourne shell does not support command history.
- File name substitution
Automatically produces a list of file names on a command line using pattern-matching characters.
For more information, see:
- Input and output redirection
Redirects input away from the keyboard and redirects output to a file or device other than the terminal. For example, input to a program can be provided from a file and redirected to the printer or to another file.
For more information, see:
- Piping
Links any number of commands together to form a complex program. The standard output of one program becomes the standard input of the next.
For more information, see the pipeline definition in Shells terminology.
- Shell variable substitution
Stores data in user-defined variables and predefined shell variables.
For more information, see: