#pressalt.cgi by Tim Brice NWS El Paso


#change station pressure to millibars
if ($ps{press} =~ /-?(\d+)\.?(\d+)|^\d+$/) {
  if ($ps{mborin} =~ millibars) {
      $press = $ps{press};
 } else {
   $press = $ps{press} * 33.8639;
  }
} else {
 print "An illegal character was entered.\n";
}

#Do some math

$pstd = 1013.25;
$pa = (1 - ($press/$pstd)**.190284) * 145366.45;
$pa1 = $pa * 0.3048;

#Output time

$~ = PS1;
write;

format PS1 =
With a station pressure of @###.## @<<<<<<<<<<<<<<<<<:
                         $ps{press}, $ps{mborin} 

You get a pressure altitude of @####.# feet or @####.# meters $pa $pa1 .