newgrp(1) [freebsd man page]

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 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

     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.

BSD
								 February 8, 2013							       BSD

NEWGRP(1)						    BSD 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.

BSD
								   June 6, 2007 							       BSD