What the different shells are for
Three different command oriented shells are available for the SCO OpenServer
system.
You can choose to work with any one of them.
The shells are as follows:
The shells
-----------------------------------------------------------------------
Name Filename Features
-----------------------------------------------------------------------
Bourne Shell /bin/sh
+ First shell to be developed.
+ Wildcards, basic command language.
+ Available on the SCO OpenServer
system.
C Shell /bin/csh
+ Different language syntax from
Bourne and Korn shell family
(similar to the C programming
language).
+ Command history recall (permits
reuse of recently issued commands
without retyping them).
+ Aliases (the ability to define
alternative names for commands).
Limited ability to redirect input
and output.
Korn Shell /bin/ksh
+ Compatible superset of Bourne shell
facilities.
+ Command history editing (edit and
reissue previously typed commands
interactively).
+ Aliases (the ability to define
alternative names for commands).
+ Job control (the ability to run
processes in the background and
manipulate background processes).
+ Extended language syntax (permits
more complex scripts to be
written).
+ Recommended as the shell of first
choice.
The SCO shell is a different type of shell: a menu-driven
interface that cannot execute scripts directly. It is discussed in
Chapter 1, ``Using SCO Shell''.
In this chapter and the next we will be concentrating on the Korn shell: specifically, on those features of the Korn shell that are also available to the Bourne shell. Where additional Korn shell facilities are introduced, they are explicitly identified as such because they are not available under the Bourne shell.
Note that we do not recommend the C shell to new users. C shell
syntax is nonstandard, and there are a number of features present in
the Bourne and Korn shells that are not present in the C shell.