Shell concepts

Before you start working with the different types of shells available for AIX you need to understand basic terminology and features.

Available shells
The following are the shells that are provided with AIX.
Shells terminology
The terms and definitions in this table are helpful in understanding shells.
Specifying a shell for a script file
When you run an executable shell script in either the Korn (the POSIX Shell) or Bourne shell, the commands in the script are carried out under the control of the current shell (the shell from which the script is started) unless you specify a different shell. When you run an executable shell script in the C shell, the commands in the script are carried out under the control of the Bourne shell (/usr/bin/bsh) unless you specify a different shell.
Shell features
There are advantages to using the shell as an interface to the system.
Character classes
You can use character classes to match file names.
Restricted shell
The restricted shell is used to set up login names and execution environments whose capabilities are more controlled than those of the regular Bourne shell.
Creating and running a shell script
A shell script is a file that contains one or more commands. Shell scripts provide an easy way to carry out tedious commands, large or complicated sequences of commands, and routine tasks. When you enter the name of a shell script file, the system executes the command sequence contained by the file.

Parent topic: Operating system shells