Linux and Unix newgrp command
Log into a new group.
newgrp [ -| -l ] [ group ] [argument]
|- | -l||Change the environment to what would be expected if the user actually logged in again as a member of the new group.|
|group||A group name from the group database or a non negative numeric group ID. Specifies the group ID to which the real and effective group IDs will be set. If group is a non-negative numeric string and exists in the group database as a group name, the numeric group ID associated with that group name will be used as the group ID.|
|argument||sh and ksh only. Options and operand of the newgrp command.|
Return you to a prompt of a new shell.