GROUP(5) BSD Reference Manual GROUP(5)
group - format of the group permissions file
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 system (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.
If YP is active, the group file may also contain lines of the format
+name:*::
which causes the specified group to be included from the group.byname YP
map. If no group name is specified, or the '+' (plus sign) appears alone
on a line, all groups are included from the YP map.
YP references may appear anywhere in the file, but the single '+' form
should be on the last line, for historical reasons. Only the first group
with a specific name encountered, whether in the group file itself, or
included via YP, will be used.
/etc/group
passwd(1), setgroups(2), crypt(3), initgroups(3), passwd(5), yp(8)
A group file format appeared in Version 6 AT&T UNIX.
The YP file format first appeared in SunOS.
The passwd(1) command does not change the group passwords.
Lines in /etc/group are limited to 1024 characters. YP groups are not af-
fected by this limit.
Groups are limited to a maximum of 200 members per group.
MirBSD #10-current July 18, 1995 1