newgrp(1) - NetBSD Manual Pages

NEWGRP(1)               NetBSD General Commands Manual               NEWGRP(1)


NAME

     newgrp -- change to a new primary group


SYNOPSIS

     newgrp [-l] [group]


DESCRIPTION

     The newgrp command changes a user to a new primary group (real and
     effective group ID) by starting a new shell.  The user remains logged in
     and the current directory and file creation mask remain unchanged.  The
     user is always given a new shell even if the primary group change fails.

     The newgrp command accepts the following options:

     -l      The environment is changed to what would be expected if the user
             actually logged in again.  This simulates a full login.

     The group is a group name or non-negative numeric group ID from the group
     database.  The real and effective group IDs are set to group or the group
     ID associated with the group name.

     If group is not specified, newgrp restores the user's real and effective
     group IDs to the user's primary group specified in the password database.
     The user's supplementary group IDs are restored to the set specified for
     the user in the group database.

     If the user is not a member of the specified group, and the group
     requires a password, the user will be prompted for the group password.


FILES

     /etc/group          The group database
     /etc/master.passwd  The user database
     /etc/passwd         A Version 7 format password file


EXIT STATUS

     If a new shell is started the exit status is the exit status of the
     shell.  Otherwise the exit status will be >0.


SEE ALSO

     csh(1), groups(1), login(1), sh(1), su(1), umask(2), group(5), passwd(5),
     environ(7)


STANDARDS

     The newgrp command conforms to IEEE Std 1003.1-2001 (``POSIX.1'').


HISTORY

     A newgrp command appeared in Version 6 AT&T UNIX.  A newgrp command
     appeared in NetBSD 5.0.


BUGS

     There is no convenient way to enter a password into /etc/group.  The use
     of group passwords is strongly discouraged since they are inherently
     insecure.  It is not possible to stop users from obtaining the encrypted
     password from the group database.

NetBSD 10.99                     June 6, 2007                     NetBSD 10.99