Common Features

The following table displays features that are common to the Bash, Korn, and C shells. Note that both the Korn shell and Bash are enhanced versions of the Bourne shell; therefore, they include all features of the Bourne shell, plus some others.



a Brace expansion is a compile-time feature in the Korn shell. Usually commercial versions don’t have it, but if you compile from source code, you do get it by default.


Redirect output.


Append to file.


Redirect input.


“Here” document (redirect input).


Pipe output.


Run process in background.


Separate commands on same line.


Home directory symbol.


Match any character(s) in filename.


Match single character in filename.

[ ]

Match any characters enclosed.


Execute in subshell.

{ }

Expand elements in list.a

' '

Substitute output of enclosed command.

" "

Partial quote (allows variable and command expansion).

' '

Full quote (no expansion).


Quote following character.

$ var

Use value for variable.


Process ID.


Command name.

$ n

n th argument (0 ≤ n ≤ 9).


All arguments as simple words.


Begin comment.


Background execution.


Break from loop statements.


Change directory.


Resume a program loop.


Display output.


Evaluate arguments.


Execute a new shell.


Foreground execution.


List previous commands.

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