CHGRP(1) BSD Reference Manual CHGRP(1)
chgrp - change group
chgrp [-R [-H | -L | -P]] [-fh] group file [...]
chgrp sets the group ID of the specified files. The options are as follows: -H If the -R option is specified, symbolic links on the command line are followed. (Symbolic links encountered in the tree traversal are not followed.) -L If the -R option is specified, all symbolic links are followed. -P If the -R option is specified, no symbolic links are followed. -R Change the group ID for the file hierarchies rooted in the files instead of just the files themselves. -f The force option ignores errors, except for usage errors. -h Change the group ID of the specified symbolic link. The -h and -R options are mutually exclusive. The -H, -L, and -P options are ignored unless the -R option is specified. In addition, these options override each other and the command's actions are determined by the last one specified. The group operand can be either a group name from the group database, or a numeric group ID. If a group name is also a numeric group ID, the operand is used as a group name. The user invoking chgrp must belong to the specified group and be the owner of the file, or be the superuser. The chgrp utility exits 0 on success or >0 if an error occurred.
/etc/group group ID file
chown(2), lchown(2), fts(3), group(5), passwd(5), symlink(7), chown(8)
The chgrp utility is expected to be POSIX 1003.2 compatible. MirBSD #10-current May 20, 2007 1