I installed this and it is working fine on 2.3.0. I changed the code a bit to take into account the number of characters. Our board uses~70 characters per line. The logic isn't perfect, but it works.
Code:
if ($maxlinessig!=0) {
$linessig = explode("\n", $signature);
if (count($linessig)>$maxlinessig) {
eval("standarderror(\"".gettemplate("error_sigtoolong")."\");");
exit;
}
//
//The intended logic here is for each line feed we must add 70 to our count, however this
//is a little overkill if the person for some reason actually presses enter here and there.
//a little slack is given
//'
if( (strlen($signature)+(count($linessig)*35)) > ($maxlinessig * 70)){
eval("standarderror(\"".gettemplate("error_sigtoolong")."\");");
exit;
}
}