NEWGRP(1)		  BSD General Commands Manual		     NEWGRP(1)

NAME
     newgrp — change to a new group

SYNOPSIS
     newgrp [-l] [group]

DESCRIPTION
     The newgrp utility creates a new shell execution environment with modi‐
     fied real and effective group IDs.

     The options are as follows:

     -l      Simulate a full login.  The environment and umask are set to what
	     would be expected if the user actually logged in again.

     If the group operand is present, a new shell is started with the speci‐
     fied effective and real group IDs.  The user will be prompted for a pass‐
     word if they are not a member of the specified group.

     Otherwise, the real, effective and supplementary group IDs are restored
     to those from the current user's password database entry.

EXIT STATUS
     The newgrp utility attempts to start the shell regardless of whether
     group IDs were successfully changed.

     If an error occurs and the shell cannot be started, newgrp exits >0.
     Otherwise, the exit status of newgrp is the exit status of the shell.

SEE ALSO
     csh(1), groups(1), login(1), sh(1), su(1), umask(1), group(5), passwd(5),
     environ(7)

STANDARDS
     The newgrp utility conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

HISTORY
     A newgrp utility appeared in Version 6 AT&T UNIX.

BUGS
     For security reasons, the newgrp utility is normally installed without
     the setuid bit.  To enable it, run the following command:

	   chmod u+s /usr/bin/newgrp

     Group passwords are inherently insecure as there is no way to stop users
     obtaining the password hash from the group database.  Their use is dis‐
     couraged.	Instead, users should simply be added to the necessary groups.

BSD			       February 8, 2013 			   BSD