#!/usr/bin/perl

# Can be used to test regular expressions.
# Provide the regular expression in the command line,
#  and then type strings, each of which will be checked 
#  against the regular expression for a match.
# To terminate, type EOF (cntl/Z or cntl/D).

# Note that $' goes in and out of scope from if to while.
#  Replace $leftover with $' in the print after the while,
#  and see the difference...

$leftover = '';

while( <STDIN> ) {
    chomp;
    if( /$ARGV[0]/ ) {
    	print "Matched: |$`<$&>";
    	$leftover = $';
    	while( $' =~ /$ARGV[0]/ ) {
    		print "$`<$&>";
    		$leftover = $';
    	}
    	print "$leftover|\n";
    }
    else {
    	print "No match.\n";
    }
}