2005-12-07 14:08:12 +00:00
|
|
|
6.10 The Restricted Shell
|
|
|
|
|
=========================
|
2002-07-17 14:10:11 +00:00
|
|
|
|
|
|
|
|
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.
|
|
|
|
|
|
