newgrp - change to a new group
newgrp [-l] group ...
The newgrp(1) utility changes the shell execution environment to have the specified real and effective group. This new shell environment keeps the working directory, file creation mask, and exported variables of the previous environment. Even if the newgrp(1) fails to assign a new group, it still creates a new shell environment.
newgrp(1) takes the following options:
The group is the name or numeric group identifier (ID) of a group in the group database. If you do not specify a group, newgrp(1) changes the real and effective group ID back to your login group.
If you are not listed as a member of the group and the group requires a password, you are prompted to enter the password. If you are listed as a member of the group, you are not prompted.
If it succeeds, the exit status is the exit status of the shell. Otherwise, it returns a value >0.
By default, Interix does not execute files with the set-user-ID (setuid) or set-group-ID (setgid) mode bit set for security reasons. If an attempt is made to execute such a file, the ENOSETUID error is returned. For more information and and instructions for enabling execution of files with these mode bits set, see The superuser account and appropriate privileges in Windows Services for UNIX Help.
Because of the security mechanisms of Windows, there is no way to get the appropriate permissions to change groups. Therefore, this command always fails to change the effective group. It does, however, create a new shell environment, as described above.
sh(1)