You're programming like a crazy man, with code going everywhere! Maybe if you pull out some of the extraneous material and things will start to make sense: 
while(<PWD>)
{
    my($name,$passwd,$uid,$gid,$gcos,$dir,$shell)=split /:/;

    $uid=$UIDS{$name} if (defined $UIDS{$name});

    $line=join ':',$name,$passwd,$uid,$gid,$gcos,$dir,$shell;
    print TMP $line;
}

[download]
Also, why use 'uname' when 'hostname' is a much better tool for finding your hostname. Not to mention the Sys::Hostname module which does an even better job.

In reply to Re: Changing UIDs by tadman
in thread Changing UIDs by TStanley

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