How do I encode HTTP GET query strings in Perl? - perl

Question

This question is somewhat related to What’s the simplest way to make a HTTP GET request in Perl?.
Before making the request via LWP::Simple I have a hash of query string components that I need to serialize/escape. What's the best way to encode the query string? It should take into account spaces and all the characters that need to be escaped in valid URIs. I figure it's probably in an existing package, but I'm not sure how to go about finding it.
use LWP::Simple;
my $base_uri = 'http://example.com/rest_api/';
my %query_hash = (spam => 'eggs', foo => 'bar baz');
my $query_string = urlencode(query_hash); # Part in question.
my $query_uri = "$base_uri?$query_string";
# http://example.com/rest_api/?spam=eggs&foo=bar+baz
$contents = get($query_uri);

Answer 1

URI::Escape is probably the most direct answer, as other have given, but I would recommend using a URI object for the entire thing. URI automatically escapes the GET parameters for you (using URI::Escape).
my $uri = URI->new( 'http://example.com' );
$uri->query_form(foo => '1 2', bar => 2);
print $uri; ## http://example.com?foo=1+2&bar=2
As an added bonus, LWP::Simple's get function will take a URI object as it's argument instead of a string.

Answer 2

URI::Escape does what you want.
use URI::Escape;
sub escape_hash {
my %hash = #_;
my #pairs;
for my $key (keys %hash) {
push #pairs, join "=", map { uri_escape($_) } $key, $hash{$key};
}
return join "&", #pairs;
}

Answer 3

URI is far simpler than URI::Escape for this. The method query_form() accepts a hash or a hashref:
use URI;
my $full_url = URI->new('http://example.com');
$full_url->query_form({"id" => 27, "order" => "my key"});
print "$full_url\n"; # http://example.com?id=27&order=my+key

Answer 4

Use the module URI to build the URL with the query parameters:
use LWP::Simple;
use URI;
my $uri_object = URI->new('http://example.com/rest_api/');
$uri_object->query_form(spam => 'eggs', foo => 'bar baz');
$contents = get("$uri_object");
I found this solution here.

Answer 5

Use LWP::UserAgent instead:
use strict;
use warnings;
use LWP::UserAgent;
my %query_hash = (spam => 'eggs', foo => 'bar baz');
my $ua = LWP::UserAgent->new();
my $resp = $ua->get("http://www.foobar.com", %query_hash);
print $resp->content;
It takes care of the encoding for you.
If you want a more generic encoding solution, see HTML::Entities.
EDIT: URI::Escape is a better choice.

Answer 6

URI::Escape is the module you are probably thinking of.