1 #!/usr/bin/perl
  2
  3 use warnings;
  4
  5 print "Enter numbers from 1 to 20 and/or letters seperated by a space:", "\n    ";
  6 print "Enter q or Q to quit", "\n";
  7 ($list = <STDIN>);
  8 chomp $list;
  9 print $list, "\n";
 10 print "length of list: " , length($list), "\n";
 11 $howlong = length($list);
 12 print "howlong = ", $howlong, "\n";
 13 $sum = 0;
 14 $pointer = 0;
 15 $hold = "";
 16 $work = "";
 17 while (!$flag and $pointer <= $howlong +1)
 18 {
 19    $work = substr($list,$pointer,1);
 20 if ($work eq "q" or $work eq "Q") {
 21  $flag = true;
 22  print "flag = , $flag, ", "\n";
 23   }
 24   if ($work ne "q" and $work ne "Q") {
 25     if ( $work =~ /^[\+-]*[0-9]*\.*[0-9]*$/ && $work !~ /^[\. ]*$/  ) {
 26      if ($work == ' ') {
 27       if ($pointer > 0) {
 28          $hold = "$hold"." + "."$work";
 29          print "pointer = ", $pointer, "\n";
 30          print "hold = ", $hold, "\n";
 31          print "work = ", $work, "\n";
 32          $sum = $sum + $work;
 33          $pointer++;
 34       }
 35       else {
 36          $hold = "$hold"."$work";
 37          $sum = ($sum + $work);
 38          $pointer++;
 39          }
 40     }
 41      else {
 42         $hold = $hold.$hold;
 43     }
 44     else {
 45        $pointer++;
 46        print "has alpha: ", $work, "\n";
 47        }
 48   }
 49   else {
 50      print ($hold, " = ", $sum, "\n");
 51       }
 52
 53 }
 54 }