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Edit File: RBASH

6.10 The Restricted Shell ========================= If Bash is started with the name 'rbash', or the '--restricted' or '-r' 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 'bash' with the exception that the following are disallowed or not performed: * Changing directories with the 'cd' builtin. * Setting or unsetting the values of the 'SHELL', 'PATH', 'ENV', or 'BASH_ENV' variables. * Specifying command names containing slashes. * Specifying a filename containing a slash as an argument to the '.' builtin command. * Specifying a filename containing a slash as an argument to the '-p' option to the 'hash' builtin command. * Importing function definitions from the shell environment at startup. * Parsing the value of 'SHELLOPTS' from the shell environment at startup. * Redirecting output using the '>', '>|', '<>', '>&', '&>', and '>>' redirection operators. * Using the 'exec' builtin to replace the shell with another command. * Adding or deleting builtin commands with the '-f' and '-d' options to the 'enable' builtin. * Using the 'enable' builtin command to enable disabled shell builtins. * Specifying the '-p' option to the 'command' builtin. * Turning off restricted mode with 'set +r' or 'set +o restricted'. These restrictions are enforced after any startup files are read. When a command that is found to be a shell script is executed (*note Shell Scripts::), 'rbash' turns off any restrictions in the shell spawned to execute the script.