opendarwin man page for sg

SG(1)                                                              User Commands                                                             SG(1)

NAME
       sg - execute command as different group ID

SYNOPSIS
       sg [-] [group [-c ] command]

DESCRIPTION
       The sg command works similar to newgrp but accepts a command. The command will be executed with the /bin/sh shell. With most shells you may
       run sg from, you need to enclose multi-word commands in quotes. Another difference between newgrp and sg is that some shells treat newgrp
       specially, replacing themselves with a new instance of a shell that newgrp creates. This doesn't happen with sg, so upon exit from a sg
       command you are returned to your previous group ID.

CONFIGURATION
       The following configuration variables in /etc/login.defs change the behavior of this tool:

       SYSLOG_SG_ENAB (boolean)
           Enable "syslog" logging of sg activity.

FILES
       /etc/passwd
           User account information.

       /etc/shadow
           Secure user account information.

       /etc/group
           Group account information.

       /etc/gshadow
           Secure group account information.

SEE ALSO
       id(1), login(1), newgrp(1), su(1), gpasswd(1), group(5), gshadow(5).

shadow-utils 4.5                                                    01/25/2018                                                               SG(1)