Changing Characters in Perl using Regular Expressions

Changing Characters in Strings Using Perl Regular Expressions

This illustrates how we can use regular expressions to swap characters. This version changes any spaces in a string to underlines which is great for moving files from Windows to Unix!

sub SpaceToUnderline
{
   my @out = @_;
   TraceScript $Paranoid, "SpaceToUnderline", "About to change string";
   for (@out)
   {
       s/\s/_/g;
   }
   return @out == 1
              ? $out[0]   # only one to return
              : @out;     # or many
}

It makes use of Perl's regular expression processing. There is a speed overhead in calling the regular expression parser but sometimes that's a cost worth bearing, as here, when the simplicity of the code outweighs the price in speed of execution.

To use this just store the result of the call in a suitable variable (or whatever)...

$ChangedString = SpaceToUnderline $OriginalString;