4.1 Overview of Features

The Bourne shell is the standard shell and provides the following features:

• Input/output redirection.

• Wildcard characters (metacharacters) for filename abbreviation.

• Shell variables for customizing your environment.

• A built-in command set for writing shell programs.

• Job control (beginning in SVR4).

The Korn shell is a backward-compatible extension of the Bourne shell. Features that are valid only in the Korn shell are so indicated.

• Command-line editing (using vi or emacs).

• Access to previous commands (command history).

• Integer arithmetic.

• More ways to match patterns and substitute variables.

• Arrays and arithmetic expressions.

• Command name abbreviation (aliasing).