opensolaris man page for group

group(4)							   File Formats 							  group(4)

NAME
       group - group file

DESCRIPTION
       The  group  file  is a local source of group information. The group file can be used in conjunction with other group sources, including the
       NIS maps group.byname and group.bygid, the NIS+ table group, or group information stored on an LDAP server. Programs use  the  getgrnam(3C)
       routines to access this information.

       The group file contains a one-line entry for each group recognized by the system, of the form:

       groupname:password: gid:user-list

       where

       groupname    The name of the group. A string consisting of lower case alphabetic characters and numeric characters. Neither a colon (:) nor
		    a NEWLINE can be part of a groupname. The string must be less than MAXGLEN-1, usually 8, characters long.

       gid	    The group's unique numerical ID (GID) within the system.

       user-list    A comma-separated list of users allowed in the group.

       The maximum value of the gid field is 2147483647. To maximize interoperability and compatibility, administrators are recommended to  assign
       groups using the range of GIDs below 60000 where possible.

       If the password field is empty, no password is demanded. During user identification and authentication, the supplementary group access list
       is initialized sequentially from information in this file. If a user is in more groups than the system is configured for, {NGROUPS_MAX},  a
       warning will be given and subsequent group specifications will be ignored.

       Malformed  entries  cause  routines that read this file to halt, in which case group assignments specified further along are never made. To
       prevent this from happening, use grpck(1B) to check the /etc/group database from time to time.

       If the number of characters in an entry exceeds 2047, group maintenance commands, such as groupdel(1M) and groupmod(1M), fail.

       Previous releases used a group entry beginning with a `+' (plus sign) or `-' (minus sign) to selectively incorporate entries from a  naming
       service	source	(for  example,	an  NIS  map  or  data	from an LDAP server) for group. If still required, this is supported by specifying
       group:compat in nsswitch.conf(4). The compat source may not be supported in future releases. Possible sources are files followed by ldap or
       nisplus.  This  has  the  effect  of incorporating information from an LDAP server or the entire contents of the NIS+ group table after the
       group file.

EXAMPLES
       Example 1 Example group File.

       The following is an example of a group file:

	 root::0:root
	 stooges:q.mJzTnu8icF.:10:larry,moe,curly

       and the sample group entry from nsswitch.conf:

	 group: files ldap

       With these entries, the group stooges will have members larry, moe, and curly, and all groups listed on the  LDAP  server  are  effectively
       incorporated after the entry for stooges.

       If the group file was:

	 root::0:root
	 stooges:q.mJzTnu8icF.:10:larry,moe,curly
	 +:

       and the group entry from nsswitch.conf:

	 group: compat

       all the groups listed in the NIS group.bygid and group.byname maps would be effectively incorporated after the entry for stooges.

SEE ALSO
       groups(1), grpck(1B), newgrp(1), groupadd(1M), groupdel(1M), groupmod(1M), getgrnam(3C), initgroups(3C), nsswitch.conf(4), unistd.h(3HEAD)

       System Administration Guide: Basic Administration

SunOS 5.11							    27 Aug 2008 							  group(4)