awk/sed/ksh script to cleanup /etc/group file

Shell Programming and Scripting
1

Many of my servers' /etc/group file have many userid's that does not exist in /etc/passwd file and they need to be deleted.
This happened due to manual manipulation of /etc/passwd files.
I need to do this for 40 servers.
Can anyone help me in achieving this? Even reducing a step or two will be greatly appreciated.
Thanks in advance.

2

Hope Perl is OK. :slight_smile:

file1:

matt:1:2:3
kristen:1:2:3
curt:1:2:3
jennifer:1:2:3

file2:

jennifer:1:2:3
kristen:1:2:3
curt:1:2:3

Here's the code:

#!/usr/bin/perl

# names in file1 not in file2
foreach (@names=`cut -d ':' -f1 file1`) {
        chomp(@names);
        $count = `grep -c $_ file2`;
        if ($count == 0)        {
                print "$_ is in file1 but not file2.\n";
        }
}

$ ./cleanup.pl
matt is in file1 but not file2.
$

Of course there's probably a really simple way to do it...I'll leave that to much smarter people.

HTH

3

Another solution:

awk ' FNR==NR{for (h=4;h<=NF;h++)a[$h]=n;next}b[$1]=n
END {for (i in a)if ((!(i in b))&&(i != "")) print i" in group file but not in passwd"
}' FS="(:)|(,)"  /etc/group /etc/passwd
4

Cool, Klashxx I'm going to study your script. Thanks for the reply.

5

Thank you all for providing me the script to take care of what I need to do.
:slight_smile:

6

Thank you for everything... but I forgot to mention that I need to get rid of only users that starts with a alpha character followed by 4 digits (ie. A9999).
Can you do this with awk or do I have to use ksh?
Thanks.

7

Hi , u can use:

awk ' FNR==NR{for (h=4;h<=NF;h++)if(match($h,/^[A-Za-z][0-9]{4}$/))a[$h]=n;next}b[$1]=n
END {for (i in a)if ((!(i in b))&&(i != "")) print i" in group file but not in passwd"
}' FS="(:)|(,)" /etc/group /etc/passwd