Hello
 
   What does it mean that the group is "(?)" for a file in Unix? The
other files have a gourp "user." I want to change the files listed as
group "user" so they will be the same as whatever the group "(?)" is.

Thank you

Is there a group defined with the name ? or (?)  ?
Or is this the way something (ls?) is trying to say no group is
defined?  ls normally displays a number in that situation.

If you've got perl (and Unix usually does) then what do you get from
this (replacing /tmp/F with the fileanme you want to test).


#!/usr/bin/perl

($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
$atime,$mtime,$ctime,$blksize,$blocks)=stat( "/tmp/F");
printf("U=%d, G=%d\n", $uid, $gid);

$group=getgrgid($gid);
if (defined($group)) {
    printf("GROUP=%s\n",  $group)
} else {
   printf("No group numbered %d\n", $gid);
}

Your experience may vary depending on exactly what flavor of Unix you
are using, but assuming anything ever remotely standard, you can do:

 ls -ln

to see the user/group by numbers (first is user, second is group) instead of name.

You can then look the group number on the system in /etc/group.

 grep 12345 /etc/group

You'll probably find an entry like:

 (?):x:12345:

The first field in the group name, which is what is normally displayed
by "ls -l" when you don't use the "-n" option.

Note: If you're on a network, the group name may not be in /etc/group
but served by a network resources such as NIS, LDAP, or similar
service.  Talk with your local network administrator in that case.


To change the group-ownership of a file, just do

 chgrp 12345 whatever you wish to change

or

 chgrp "(?)" whatever you wish to change


Good luck!

the group is not valid.  It might happen when you create the group
before, then remove it