newgrp

NEWGRP(1)                    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 modified
     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 specified
     effective and real group IDs.  The user will be prompted for a password 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
     Group passwords are inherently insecure as there is no way to stop users
     obtaining the crypted passwords from the group database.  Their use is
     discouraged.

macOS 12.1                        May 23, 2002                        macOS 12.1