Can you please tell me how to cram the contents of capture groups into a hash in perl?

Example:

I have a file:

https://www.youtube.com/watch?v=5qap5aO4i9A
http://example.com:8080/r/p?s=10&z=11#text
https://exapmle.com/test/p?var=100
http://test.org:81/
https://main.org
gopher://gopher.floodgap.com/gopher/relevance.txt
file:///home/user/.profile
gemini://transjovian.org/

I want to break each line of this file into a set of key - value and add them to the hash, then output the contents of that hash.

The content of my script:

#!/usr/bin/env perl

use strict;
use utf8;
use warnings;
use feature qw(say);
use Data::Dumper;

sub parse_url {
    my ($url) = @_;
    if ($url =~ m#(.*):/(.*)#) {
        my (%hash, $scheme, $domain, $port, $path, $query_string, $anchor);
        $url =~ m!^(?<scheme>[^:] ):/{2,3}(?<domain>[^:/] )(?::(?<port>(?:\d )?)?)(?<path>(?:/[^?] )?)(?:\?(?<query_string>(?:[^\#] )?)?)(?:\#(?<anchor>(?:. )?)?)!;

        if(defined($scheme)) { $hash{'scheme'} = $scheme; }
        if(defined($domain)) { $hash{'domain'} = $domain; }
        if(defined($port)) { $hash{'port'} = $port; }
        if(defined($path)) { $hash{'path'} = $path; }
        if(defined($query_string)) { $hash{'query_string'} = $query_string; }
        if(defined($anchor)) { $hash{'anchor'} = $anchor; }
        return %hash;
    }
}

while (my $row = <>) {
    chomp $row;
    say $row;
    my %hash = parse_url($row);
    print Dumper \%hash;
}

I want to get this output:

https://www.youtube.com/watch?v=5qap5aO4i9A
$VAR1 = {
    scheme         => 'https',
    domain         => 'www.youtube.com',
    path           => '/watch',
    query_string   => 'v=5qap5aO4i9A',
};
http://example.com:8080/r/p?s=10&z=11#text
$VAR1 = {
    scheme         => 'http',
    domain         => 'example.com',
    port           => '8080',
    path           => '/r/p',
    query_string   => 's=10&z=11',
    anchor         => 'text',
};
https://exapmle.com/test/p?var=100
$VAR1 = {
    scheme         => 'http',
    domain         => 'example.com',
    path           => '/test/p',
    query_string   => 'var=100',
};
http://test.org:81/
$VAR1 = {
    scheme         => 'http',
    domain         => 'test.org',
    port           => '81',
};
https://main.org
$VAR1 = {
    scheme         => 'https',
    domain         => 'main.org',
};
gopher://gopher.floodgap.com/gopher/relevance.txt
$VAR1 = {
    scheme         => 'gopher',
    domain         => 'gopher.floodgap.com',
    path           => '/gopher/relevance.txt',
};
file:///home/user/.profile
$VAR1 = {
    scheme         => 'file',
    path           => '/home/user/.profile',
};
gemini://transjovian.org/
$VAR1 = {
    scheme         => 'gemini',
    domain         => 'transjovian.org',
};

But I get this conclusion:

https://www.youtube.com/watch?v=5qap5aO4i9A
$VAR1 = {};
http://example.com:8080/r/p?s=10&z=11#text
$VAR1 = {};
https://exapmle.com/test/p?var=100
$VAR1 = {};
http://test.org:81/
$VAR1 = {};
https://main.org
$VAR1 = {};
gopher://gopher.floodgap.com/gopher/relevance.txt
$VAR1 = {};
file:///home/user/.profile
$VAR1 = {};
gemini://transjovian.org/
$VAR1 = {};

Thank you for your help!

CodePudding user response：

You can use the special variable % (or %{^CAPTURE}) to get the named captures like this:

use strict;
use utf8;
use warnings;
use feature qw(say);
use open ':std', ':encoding(utf-8)';
use Data::Dumper;

sub parse_url {
    my ($url) = @_;
    if ($url =~ m#(.*):/(.*)#) {
        $url =~ m!
           ^(?<scheme>[^:] ):/{2,3}
            (?<domain>[^:/] )
              (?::?(?<port>(?:\d )?)?)
              (?<path>(?:/[^?] )?)
              (?:\??(?<query_string>(?:[^\#] )?)?)
              (?:\#?(?<anchor>(?:. )?)?)
        !x;
        my %hash = % ;
        return %hash;
    }
}

while (my $row = <>) {
    chomp $row;
    say $row;
    my %hash = parse_url($row);
    if (%hash) {
        print Dumper \%hash;
    }
    else {
        say "  -> No match";
    }
}

Output:

 $VAR1 = {
          'anchor' => 'text',
          'path' => '/r/p',
          'query_string' => 's=10&z=11',
          'port' => '8080',
          'scheme' => 'http',
          'domain' => 'example.com'
        };
https://www.youtube.com/watch?v=5qap5aO4i9A
$VAR1 = {
          'scheme' => 'https',
          'domain' => 'www.youtube.com',
          'port' => '',
          'anchor' => '',
          'query_string' => 'v=5qap5aO4i9A',
          'path' => '/watch'
        };
https://exapmle.com/test/p?var=100
$VAR1 = {
          'port' => '',
          'scheme' => 'https',
          'anchor' => '',
          'path' => '/test/p',
          'domain' => 'exapmle.com',
          'query_string' => 'var=100'
        };
http://test.org:81/
$VAR1 = {
          'scheme' => 'http',
          'domain' => 'test.org',
          'port' => '81',
          'anchor' => '',
          'query_string' => '/',
          'path' => ''
        };
https://main.org
$VAR1 = {
          'port' => '',
          'scheme' => 'https',
          'domain' => 'main.org',
          'anchor' => '',
          'path' => '',
          'query_string' => ''
        };
gopher://gopher.floodgap.com/gopher/relevance.txt
$VAR1 = {
          'domain' => 'gopher.floodgap.com',
          'scheme' => 'gopher',
          'port' => '',
          'query_string' => '',
          'path' => '/gopher/relevance.txt',
          'anchor' => ''
        };
file:///home/user/.profile
$VAR1 = {
          'port' => '',
          'scheme' => 'file',
          'domain' => 'home',
          'anchor' => '',
          'path' => '/user/.profile',
          'query_string' => ''
        };
gemini://transjovian.org/
$VAR1 = {
          'domain' => 'transjovian.org',
          'scheme' => 'gemini',
          'port' => '',
          'query_string' => '/',
          'path' => '',
          'anchor' => ''
        };