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group(4) [opensolaris man page]

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)

Check Out this Related Man Page

groupmod(1M)															      groupmod(1M)

NAME

       groupmod - modify a group on the system

SYNOPSIS

       alternate_password_file] gid name] userlist] group

DESCRIPTION

       The command modifies a group on the system by altering the appropriate entry in the file.

       The  command  must be used with the group argument, which is the name of the group to be modified.  The name consists of a string of print-
       able characters that may not include a colon or newline

       Refer to usergroupname(5) to understand the functionality changes with the Numeric User Group Name feature.

   Options
       The command uses the following options:

	      Specify the path to the alternate password file. When this option is
			specified, user information is looked up in this file, instead of

			If specified, the option should used as the first option.

	      Change the value of the group
			ID to gid.  gid must be a non-negative decimal integer less than as defined in the header file.

	      Allow the gid to be non-unique (that is, a duplicate).

	      Change the name of the group to
			name.  name consists of a string of printable characters that may not include a colon or newline

	      Add	userlist to the supplementary group membership list of group.  It should be used in conjunction with option.

	      Modify the supplementary group membership list of
			group to userlist.  It should be used in conjunction with option.

	      Delete	userlist from the supplementary group membership list of group.  It should be used in conjunction with option.

	      Specifies the list of users for modifying the supplementary
			group membership list of the group.  When options and options are not specified, is assumed.

   NIS
       The command is aware of NIS user entries.  Only local groups may be modified with Attempts to modify an NIS group will result in an  error.
       NIS groups must be administered from the NIS server.  If is used on a system where NIS is installed, it may fail with the error

       (return	value  6) if the group specified is an NIS group (see group(4)).  However, NIS groups are checked when verifying uniqueness of the
       new gid or new group name, which may result in the above error, or the error

       (return value 4).

RETURN VALUE

       The command exits with one of the following values:

	      No error.

	      Invalid command syntax.

	      Invalid argument supplied to an option.

	      gid  is not unique (when is not used).

	      group
		   does not exist.

	      group
		   is not unique.

	      Cannot modify the
		   file.

	      file or
		   file busy. Another command may be modifying the file.

	      Unable to open
		   file or the file is non-existent.

	      Exceeding permissible limit of maximum members in a group.
		   The file is not modified.

EXAMPLES

       Change the group ID of the group to in the file if the group exists.  This is done even if the group ID is already in use.

       Change the name of to in the file if the group does not already exist.

WARNINGS

       Because many users try to write to the file simultaneously, a password locking mechanism was devised.  If this locking fails  after  subse-
       quent retrying, terminates.

FILES

SEE ALSO

       users(1), groupadd(1M), groupdel(1M), logins(1M), useradd(1M), userdel(1M), usermod(1M), group(4), usergroupname(5).

STANDARDS CONFORMANCE

																      groupmod(1M)
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