bash: The Restricted Shell
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1 6.10 The Restricted Shell
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1 If Bash is started with the name 'rbash', or the '--restricted' or '-r'
1 option is supplied at invocation, the shell becomes restricted. A
1 restricted shell is used to set up an environment more controlled than
1 the standard shell. A restricted shell behaves identically to 'bash'
1 with the exception that the following are disallowed or not performed:
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1 * Changing directories with the 'cd' builtin.
1 * Setting or unsetting the values of the 'SHELL', 'PATH', 'ENV', or
1 'BASH_ENV' variables.
1 * Specifying command names containing slashes.
1 * Specifying a filename containing a slash as an argument to the '.'
1 builtin command.
1 * Specifying a filename containing a slash as an argument to the '-p'
1 option to the 'hash' builtin command.
1 * Importing function definitions from the shell environment at
1 startup.
1 * Parsing the value of 'SHELLOPTS' from the shell environment at
1 startup.
1 * Redirecting output using the '>', '>|', '<>', '>&', '&>', and '>>'
1 redirection operators.
1 * Using the 'exec' builtin to replace the shell with another command.
1 * Adding or deleting builtin commands with the '-f' and '-d' options
1 to the 'enable' builtin.
1 * Using the 'enable' builtin command to enable disabled shell
1 builtins.
1 * Specifying the '-p' option to the 'command' builtin.
1 * Turning off restricted mode with 'set +r' or 'set +o restricted'.
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1 These restrictions are enforced after any startup files are read.
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11 When a command that is found to be a shell script is executed (⇒
Shell Scripts), 'rbash' turns off any restrictions in the shell
1 spawned to execute the script.
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