Eww. Don't loop over a hash to find an element: 
foreach $key (keys %UIDS) {
  if ($key eq $name) {
    $uid=$UIDS{$key};
     $line=join ':',$name,$passwd,$uid,$gid,$gcos,$dir,$shell;
    print TMP $line;
  }
  else {
     $line=join ':',$name,$passwd,$uid,$gid,$gcos,$dir,$shell;
    print TMP $line;
  }
}

[download]
Use the exists() function like you did before: 
$uid = $UIDS{$name} if exists $UIDS{$name};
print TMP join ':', $name, $passwd, $uid, $gid, $gcos, $dir, $shell;

[download]


japhy -- Perl and Regex Hacker

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

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