Provided by: bash_5.2.15-2ubuntu1_amd64 bug

NAME

       rbash - restricted bash, see bash(1)

RESTRICTED SHELL

       If  bash  is  started with the name rbash, or the -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.  It behaves identically to bash with the exception
       that the following are disallowed or not performed:

       •      changing directories with cd

       •      setting or unsetting the values of SHELL, PATH, ENV, or BASH_ENV

       •      specifying command names containing /

       •      specifying a filename containing a / 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 command to replace the shell with another command

       •      adding  or  deleting  builtin  commands  with  the  -f and -d options to the enable
              builtin command

       •      using the enable builtin command to enable disabled shell builtins

       •      specifying the -p option to the command builtin command

       •      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,  rbash  turns  off  any
       restrictions in the shell spawned to execute the script.

SEE ALSO

       bash(1)