Change to a new group
newgrp [-l|-s] [group]
The newgrp utility starts a new shell with a new real and effective group ID. The user remains logged in and the current directory doesn't change, but file access permissions are based on the new real and effective group IDs.
|This utility needs to have the setuid (“set user ID”) bit set in its permissions. If you use mkefs, mketfs, or mkifs on a Windows host to include this utility in an image, use the perms attribute to specify its permissions explicitly, and the uid and gid attributes to set the ownership correctly.|
If no operands are specified, newgrp changes the group ID back to the group identified in the invoking user's entry in /etc/passwd.
If you don't use the -l option, the environment variables remain unchanged.
Note that group passwords aren't supported in QNX Neutrino. Only the user root may change the group ID to a group that it doesn't belong to.
See the passwd utility “Files” section for a brief description of the format of these files.
Managing User Accounts in the Neutrino User's Guide