This manual page is for Mac OS X version 10.6.3

Reading manual pages

GROUP(5)                                   BSD File Formats Manual                                  GROUP(5)

NAME
     group -- format of the group permissions file

DESCRIPTION
     The file </etc/group> consists of newline separated ASCII records, one per group, containing four colon
     `:' separated fields. These fields are as follows:
           group     Name of the group.
           passwd    Group's encrypted password.
           gid       The group's decimal ID.
           member    Group members.

     The group field is the group name used for granting file access to users who are members of the group.
     The gid field is the number associated with the group name.  They should both be unique across the sys-tem system
     tem (and often across a group of systems) since they control file access.  The passwd field is an
     optional encrypted password.  This field is rarely used and an asterisk is normally placed in it rather
     than leaving it blank.  The member field contains the names of users granted the privileges of group.
     The member names are separated by commas without spaces or newlines.  A user is automatically in a
     group if that group was specified in their /etc/passwd entry and does not need to be added to that
     group in the /etc/group file.

INTERACTION WITH DIRECTORY SERVICES
     Processes generally find group records using one of the getgrent(3) family of functions.  On Mac OS X,
     these functions interact with the DirectoryService(8) daemon, which reads the /etc/group file as well
     as searching other directory information services to determine groups and group membership.

FILES
     /etc/group

SEE ALSO
     passwd(1), setgroups(2), crypt(3), getgrent(3), initgroups(3), passwd(5), DirectoryService(8)

BUGS
     The passwd(1) command does not change the group passwords.

HISTORY
     A group file format appeared in Version 6 AT&T UNIX.

Mac OS X                                        July 18, 1995                                       Mac OS X