Anyone already have a script to do this?

[S-un-B-ix-S]

We are trying to clean up our password files, and it has come to light that there are a large number of users that do not have a valid GID value.

Does anyone have a script that go through each user and check whether their GID is valid (per /etc/groups) and if it not, put that output into a list?

[James R. Ferguson · Accepted solution]

Hi:

This will help:

# cat ./badgid
#!/usr/bin/perl
use strict;
use warnings;

my %gids;
my ( $name, $uid, $gid );

while ( ( undef, undef, $gid ) = getgrent ) {
$gids{$gid}++;
}
while ( ( $name, undef, $uid, $gid ) = getpwent ) {
print "uid $uid for user '$name' with gid $gid is bogus\n"
unless defined $gids{$gid};
}
1;

...This script caches the 'gid' of the group database and then proceeds to sequentially examine every user record's 'gid'.

Silenece is golden. That is, the last of output means that all 'gid's are valid. Unmatched records are produce:

uid 1002 for user 'dummy' with gid 220 is bogus

Regards!

...JRF...

[Jeff_Traigle]

Not tested, but something like this should work:

#!/usr/bin/sh

USERLIST=/var/tmp/users_with_invalid_gid.txt
USERS=$(awk -F: '{print $1}' /etc/passwd)

for USER in ${USERS}
do
GID=$(grep ^${USER}: /etc/passwd | awk -F: '{print $4}')
if [ $(grep -c :${GID}: /etc/group) -eq 0 ]
then
echo ${USER} >> ${USERLIST}
fi
done

[Peter Nikitka]

Hi,

the command 'pwck' - part of the OS - will be a help for you as well. Just check the man page!

mfG Peter

[James R. Ferguson]

Hi (again):

The 'pwck' and/or 'grpck' may not discern inter user-group file inconsistencies.

Hence, my simple Perl script.

Regards!

...JRF...