Manual Pages for UNIX Operating System command usage for man group

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,  or group information stored on an LDAP server.
     Programs use the getgrnam(3C) routines to access this infor-
     mation.


     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 can not
                  exceed, MAXGLEN-1, which is usually eight char-
                  acters.


     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  maxim-
     ize  interoperability  and compatibility, administrators are
     recommended to assign groups using the range of  GIDs  below
     60000 where possible.


     A password can be demanded by newgrp(1) if the  group  pass-
     word  field  is not empty. The only way to create a password
     for a group is to use passwd(1),  then  cut  and  paste  the
     password from /etc/shadow to /etc/group. Group passwords are
     antiquated and not often used.






SunOS 5.11          Last change: 22 Feb 2010                    1






File Formats                                             group(4)



     During user identification and authentication,  the  supple-
     mentary  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 is
     given and subsequent group specifications is 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 might not be supported
     in future releases. A possible sources is files followed  by
     ldap.  This has the effect of incorporating information from
     an LDAP server after the group file.

EXAMPLES
     Example 1 An 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  has  members  larry,
     moe, and curly, and all groups listed on the LDAP server are



SunOS 5.11          Last change: 22 Feb 2010                    2






File Formats                                             group(4)



     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          Last change: 22 Feb 2010                    3