rsh -- invoke a restricted shell (command interpreter)


rsh [ flags ] [ name [ arg1 ... ] ]


rsh is a restricted version of the standard command interpreter, sh(C). It is used to set up login names and execution environments whose capabilities are more controlled than those of the standard shell. The actions of rsh are identical to those of sh, except that changing directory with cd, setting the value of $PATH, using command names containing slashes, and redirecting output using > and >> are all disallowed.

When invoked with the name -rsh, rsh reads the user's .profile (from $HOME/.profile). It acts as the standard sh while doing this, except that an interrupt causes an immediate exit, instead of causing a return to command level. The restrictions above are enforced after .profile is interpreted.

When a command to be executed is found to be a shell procedure, rsh invokes sh to execute it. Thus, it is possible to provide shell procedures to the end user that have access to the full power of the standard shell, while restricting the user to a limited menu of commands; this scheme assumes that the end user does not have write and execute permissions in the same directory.

The net effect of these rules is that the writer of the .profile has complete control over user actions, by performing guaranteed setup actions, then leaving the user in an appropriate directory (probably not the login directory).

rsh is actually just a link to sh and any flags arguments are the same as for sh.

The system administrator often sets up a directory of commands that can be safely invoked by rsh.

Open UNIX 8 compatibility notes

When running ACP on Open UNIX 8 and UnixWare 7 systems, set OSRCMDS=on to use the SCO OpenServer version of the <rsh> command. This provides the expected behaviors for SCO OpenServer applications. The SCO OpenServer version of this command is also provided on Open UNIX 8 systems under the OSP feature See the Running SCO OpenServer Applications topic in the Open UNIX 8 documentation set.

See also

profile(M), sh(C)

Standards conformance

rsh is conformant with AT&T SVID Issue 2.
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003