Regular Expressions

Substitutions

• To supply a replacement to be automatically inserted in place of the matched text, use the construct "s/regexp/replacestring/".
• To make the replacement take place for all possible matches (instead of simply the first) use the construct "s/regexp/replacestring/g".
• You may (and will) use the $1, $2, $3... variables to great advantage.
• Example:
  

  #!/usr/bin/perl -w
  use strict;
  
  my ($theVar);
  
  # Processor
  $theVar = "john smith";
  print "($theVar)\n";
  
  if ($theVar =~ s/john /jonathan /) {
      print "($theVar)\n";  # Expand name
  }
  if ($theVar =~ s/(.+)\s(.+)/$2 $1/) {
      print "($theVar)\n";  # Swap first and last name
  }