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group(5) [freebsd man page]

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

group -- format of the group permissions file DESCRIPTION
The group file is the local source of group information. It can be used in conjunction with the Hesiod domain `group', and the NIS maps `group.byname' and `group.bygid', as controlled by nsswitch.conf(5). The file 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. Lines whose first non-whitespace character is a pound-sign (#) are comments, and are ignored. Blank lines that consist only of spaces, tabs or newlines are also ignored. 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 associ- ated 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 group file. IMPLEMENTATION NOTES
The passwd(1) command does not change the group passwords. The pw(8) utility's groupmod command should be used instead. LIMITS
There are various limitations which are explained in the function where they occur; see section SEE ALSO. In older implementations, a group cannot have more than 200 members. The maximum line length of /etc/group is 1024 characters. Longer lines will be skipped. This limitation disappeared in FreeBSD 3.0. Older binaries that are statically linked, depend on old shared libraries, or non-FreeBSD binaries in compatibility mode may still have this limit. FILES
/etc/group SEE ALSO
newgrp(1), passwd(1), setgroups(2), crypt(3), getgrent(3), initgroups(3), nsswitch.conf(5), passwd(5), chkgrp(8), pw(8), yp(8) HISTORY
A group file format appeared in Version 6 AT&T UNIX. Support for comments first appeared in FreeBSD 3.0. BSD
February 8, 2013 BSD

Check Out this Related Man Page

NEWGRP(1)						    BSD General Commands Manual 						 NEWGRP(1)

newgrp -- change to a new primary group SYNOPSIS
newgrp [-l] [group] DESCRIPTION
The newgrp command changes a user to a new primary group (real and effective group ID) by starting a new shell. The user remains logged in and the current directory and file creation mask remain unchanged. The user is always given a new shell even if the primary group change fails. The newgrp command accepts the following options: -l The environment is changed to what would be expected if the user actually logged in again. This simulates a full login. The group is a group name or non-negative numeric group ID from the group database. The real and effective group IDs are set to group or the group ID associated with the group name. If group is not specified, newgrp restores the user's real and effective group IDs to the user's primary group specified in the password database. The user's supplementary group IDs are restored to the set specified for the user in the group database. If the user is not a member of the specified group, and the group requires a password, the user will be prompted for the group password. FILES
/etc/group The group database /etc/master.passwd The user database /etc/passwd A Version 7 format password file EXIT STATUS
If a new shell is started the exit status is the exit status of the shell. Otherwise the exit status will be >0. SEE ALSO
csh(1), groups(1), login(1), sh(1), su(1), umask(2), group(5), passwd(5), environ(7) STANDARDS
The newgrp command conforms to IEEE Std 1003.1-2001 (``POSIX.1''). HISTORY
A newgrp command appeared in Version 6 AT&T UNIX. A newgrp command appeared in NetBSD 5.0. BUGS
There is no convenient way to enter a password into /etc/group. The use of group passwords is strongly discouraged since they are inherently insecure. It is not possible to stop users from obtaining the encrypted password from the group database. BSD
June 6, 2007 BSD

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