group(5)group(5)Namegroup - group file
The file is an ASCII file that contains the following information for
Numerical group ID
Comma-separated list of all users allowed in the group
Each group name is separated from the next by a new line. The fields
are separated by colons. If the password field is null, no password is
Because of the encrypted passwords, it can and does have general read
permission and can be used, for example, to map numerical group IDs to
The database can be distributed in a network by a naming service, such
as Yellow Pages or BIND/Hesiod. See the Guide to the Yellow Pages Ser‐
vice or the Guide to the BIND/Hesiod Service for setup information.
No more than 200 users are allowed in any group. Any user names which
appear on the line after the 200th name are ignored. In addition, the
total number of characters in a line in the group file cannot exceed
1820. If the number of characters on the line approaches 1800, care
should be taken to avoid any extra spaces or tabs on the line. Each
name should be separated solely by a comma to maximize the number of
users on the line.
The command will not change the passwords.
Increasing the number of groups that a user is in beyond 8 can affect
services that use SUN RPC. The version of SUN RPC shipped with ULTRX
V4.2 supports up to 32 groups. Prior versions supported users being in
up to 8 groups. Users who increase the number of groups that they are
a member of to more than 8 will not be able to NFS mount file systems
from ULTRIX servers older than V4.2. If root group membership is
increased to more than 8 groups on a V4.2 system, the YP service may
not work if that V4.2 system is in a mixed YP server environment where
there are both V4.2 and previous releases of YP servers. Again, this
incompatibility can only occur if a user's or root's group membership
is increased to more than 8 groups.
FilesSee Alsopasswd(1), setgroups(2), crypt(3), getgrent(3), initgroups(3x),
Guide to the BIND/Hesiod Service
Guide to the Yellow Pages Service