Perl Replacing a complex regular expression with simpler method - regex

Question

I have the following code:
#!/usr/bin/perl
use strict;
use warnings;
#use diagnostics;
use URI qw( );
my #insert_words = qw(HELLO GOODBYE);
while (<DATA>) {
chomp;
my $url = URI->new($_);
my $query = $url->query;
foreach (#insert_words) {
# Use package vars to communicate with /(?{})/ blocks.
local our $insert_word = $_;
local our #queries;
if (defined $query) {
$query =~ m{
^(.*[/=])([^/=&]*)((?:[/=&].*)?)\z
(?{
if (length $2) {
push #queries, "$1$insert_word$2$3";
push #queries, "$1$insert_word$3";
push #queries, "$1$2$insert_word$3";
}
})
(?!)
}x;
}
if (#queries) {
for (#queries) {
$url->query($_);
print $url, "\n";
}
}
else {
print $url, "\n";
}
}
}
__DATA__
http://www.example.com/index.php?route=9&other=7
The above piece of code works correctly and produces the following output:
http://www.example.com/index.php?route=9&other=HELLO7 <-- precedes the query parameter
http://www.example.com/index.php?route=9&other=HELLO <-- replaces the query parameter
http://www.example.com/index.php?route=9&other=7HELLO <-- succeeds the query parameter and so on for the rest of them....
http://www.example.com/index.php?route=HELLO9&other=7
http://www.example.com/index.php?route=HELLO&other=7
http://www.example.com/index.php?route=9HELLO&other=7
http://www.example.com/index.php?route=9&other=GOODBYE7
http://www.example.com/index.php?route=9&other=GOODBYE
http://www.example.com/index.php?route=9&other=7GOODBYE
http://www.example.com/index.php?route=GOODBYE9&other=7
http://www.example.com/index.php?route=GOODBYE&other=7
http://www.example.com/index.php?route=9GOODBYE&other=7
What I am trying to do
I am trying to get exactly the same output as shown above (so foreach #insert_words precede, replace and succeed each query parameter in the url), but I would like to replace the complicated regular expression method with a simpler, more easily understandable method, but I don't know the best way of going about it.
Your help with this will be much appreciated, many thanks

Answer 1

It is described in the documentation for URI how to handle queries. The URI::QueryParam module supplies the query_param subroutine that allows interaction with the queries.
use strict;
use warnings;
use URI;
use URI::QueryParam;
my #words = qw(HELLO GOODBYE);
my $URL = <DATA>;
my $uri = URI->new($URL);
for my $key ($uri->query_param) { # the keys of the query
my $org = $uri->query_param($key); # keep original value
for my $word (#words) {
for ("$org$word", $word, "$word$org") {
$uri->query_param($key, $_); # set new value
print $uri->as_string, $/; # print new uri
}
}
$uri->query_param($key, $org); # restore original value
}
__DATA__
http://www.example.com/index.php?route=9&other=7
Output:
http://www.example.com/index.php?route=9HELLO&other=7
http://www.example.com/index.php?route=HELLO&other=7
http://www.example.com/index.php?route=HELLO9&other=7
http://www.example.com/index.php?route=9GOODBYE&other=7
http://www.example.com/index.php?route=GOODBYE&other=7
http://www.example.com/index.php?route=GOODBYE9&other=7
http://www.example.com/index.php?route=9&other=7HELLO
http://www.example.com/index.php?route=9&other=HELLO
http://www.example.com/index.php?route=9&other=HELLO7
http://www.example.com/index.php?route=9&other=7GOODBYE
http://www.example.com/index.php?route=9&other=GOODBYE
http://www.example.com/index.php?route=9&other=GOODBYE7