16.3 C Shell

16.4 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. The Rsh or bsh -r command opens the restricted shell. The behavior of these commands is identical to those of the bsh command, except that the following actions are not allowed:

• Changing the directory (with the cd command)

• Setting the value of PATH or SHELL variables

• Specifying path or command names containing a / (slash)

• Redirecting output

If the restricted shell determines that a command to be run is a shell procedure, it uses the Bourne shell to run the command. In this way, it is possible to provide an end user with shell procedures that access the full power of the Bourne shell while imposing a limited menu of commands. This scheme assumes that the end user does not have write and execute permissions in the same directory.

16.5 Setting the Shell Environment