Transform a string to a hash - perl

Question

Is there any way/lib to transform a string to a hash ?
I have such string
{"hello"=>["world","perl"],"foo"=>"bar"}
and I would like to access the different values like if it was a hash
Thank you

Answer 1

Convert the string with Perl data structure to a string with JSON data structure by substitute => with : and decode it with JSON package.
#!/usr/bin/env perl
use warnings FATAL => 'all';
use strict;
use Data::Dumper;
use JSON qw(decode_json); # use JSON::XS for more performance
my $string = '{"hello"=>["world","perl"],"foo"=>"bar"}';
$string =~ s/"=>/":/g;
print Dumper(decode_json($string));
Output
$VAR1 = {
'hello' => [
'world',
'perl'
],
'foo' => 'bar'
};

Answer 2

Using eval():
#!/usr/bin/env perl
use strict;
use Data::Dumper;
my $string = qw( {"hello"=>["world","perl"],"foo"=>"bar"} );
print "String: $string\n";
my $hash = eval($string);
print "Hash: ", Dumper($hash), "\n";
Output
String: {"hello"=>["world","perl"],"foo"=>"bar"}
Hash: $VAR1 = {
'foo' => 'bar',
'hello' => [
'world',
'perl'
]
};
Using reval() and Safe if you are at all concerned about the input:
#!/usr/bin/env perl
use strict;
use Safe;
use Data::Dumper;
my $string = qw( {"hello"=>["world","perl"],"foo"=>"bar"} );
print "String: $string\n";
my $compartment = new Safe;
my $hash = $compartment->reval($string);
print $# ? "reval error: $#" : ("Hash: ", Dumper($hash)), "\n";

Answer 3

If you don't mind me plugging one of my own modules: Config::Perl uses PPI to parse strings like that, with no need for eval:
use warnings;
use strict;
use Data::Dumper; # Debug
use Config::Perl;
my $str = q( {"hello"=>["world","perl"],"foo"=>"bar"} );
my $data = Config::Perl->new->parse_or_die(\$str)->{_}[0];
print Dumper($data); # Debug
Output:
$VAR1 = {
'hello' => [
'world',
'perl'
],
'foo' => 'bar'
};
(The above code assumes that you've only got a single hash ref in your data, if you've got variations, you'll have to look at the whole data structure returned by parse_or_die.)