Parsing a string to a hash

parsing, perl, regex

Solution

You can `split` the string on a "," and then use a `map` to create the hash:

#!/usr/bin/env perl

use strict;
use warnings;

my $str = 'https://gitlab.me.com/api/v3/projects/all?page=2&per_page=5; rel="next", https://gitlab.me.com/api/v3/projects/all?page=1&per_page=5; rel="first", https://gitlab.me.com/api/v3/projects/all?page=8&per_page=5; rel="last"';

my %hash = map { 
    my ($v, $k) = $_ =~ /\s*([^;]+);\s*rel="([^"]+)".*/; 
    $k => $v;
} split ',', $str;

foreach my $key (keys %hash) {
    print "$key => $hash{$key}\n"
}

output:

first => https://gitlab.me.com/api/v3/projects/all?page=1&per_page=5
next => https://gitlab.me.com/api/v3/projects/all?page=2&per_page=5
last => https://gitlab.me.com/api/v3/projects/all?page=8&per_page=5

update

With the new string you could do:

$str = q(<https://gitlab.me.com/api/v3/projects/all?page=2&per_page=5>; rel="next", <https://gitlab.me.com/api/v3/projects/all?page=1&per_page=5>; rel="first", <https://gitlab.me.com/api/v3/projects/all?page=8&per_page=5>; rel="last");

my %hash = map { 
    my ($v, $k) = $_ =~ /<([^>]+)>;\s*rel="([^"]+)".*/; 
    $k => $v;
} split ',', $str;

to get the same result.

Problem

I have a string: ``` <https://gitlab.me.com/api/v3/projects/all?page=2&per_page=5>; rel="next", <https://gitlab.me.com/api/v3/projects/all?page=1&per_page=5>; rel="first", <https://gitlab.me.com/api/v3/projects/all?page=8&per_page=5>; rel="last" ``` So the format is ``` (<val>; rel="key")* ``` And I want to parse that to a hash with the following format: ``` next => https://gitlab.me.com/api/v3/projects/all?page=2&per_page=5 first => https://gitlab.me.com/api/v3/projects/all?page=1&per_page=5 last => https://gitlab.me.com/api/v3/projects/all?page=8&per_page=5 ``` In Java I would use a regex pattern to extract each key => value pair and put them into a map. The pattern would be something like: ``` <([^>]++)>;\s*rel="([^"]++)" ``` Which would give me the key in the second match group and the value in the first. Would the same approach be the best way to achieve this is Perl, or is there something snazzier I could do? P.S. the reason I'm using Perl rather than Java is that the server doesn't have Java.

Original source