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.

EXAMPLES
Create a new group, foo, with pw(8):

    pw group add foo

Set the group password:

    pw group mod foo -h 0

As a non-root user, switch to the group:

    newgrp foo

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 p1003.1-2001.

HISTORY
A newgrp utility appeared in 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 discouraged. Instead, users should simply be added to the necessary groups.