Linux Know-How provides a collection of introductory texts on often needed Linux skills.

The restricted shell

When invoked as rbash or with the --restricted or -r option, the following happens:

  • The cd built-in is disabled.

  • Setting or unsetting SHELL, PATH, ENV or BASH_ENV is not possible.

  • Command names can no longer contain slashes.

  • Filenames containing a slash are not allowed with the . (source) built-in command.

  • The hash built-in does not accept slashes with the -p option.

  • Import of functions at startup is disabled.

  • SHELLOPTS is ignored at startup.

  • Output redirection using >, >|, ><, >&, &> and >> is disabled.

  • The exec built-in is disabled.

  • The -f and -d options are disabled for the enable built-in.

  • A default PATH cannot be specified with the command built-in.

  • Turning off restricted mode is not possible.

When a command that is found to be a shell script is executed, rbash turns off any restrictions in the shell spawned to execute the script.

More information:

Last Update: 2010-12-16