If Bash is started with the name
rbash, or the
option is supplied at invocation, the shell becomes restricted.
A restricted shell is used to
set up an environment more controlled than the standard shell.
A restricted shell behaves identically to
with the exception that the following are disallowed or not performed:
execbuiltin to replace the shell with another command.
enablebuiltin command to enable disabled shell builtins.
These restrictions are enforced after any startup files are read.
When a command that is found to be a shell script is executed
(see Shell Scripts),
rbash turns off any restrictions in
the shell spawned to execute the script.