Store and read hash and array in files in Perl

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You’re looking for data serialisation. Popular choices that are robust are Sereal, JSON::XS and YAML::XS. Lesser known formats are: ASN.1, Avro, BERT, BSON, CBOR, JSYNC, MessagePack, Protocol Buffers, Thrift.

Other often mentioned choices are Storable and Data::Dumper (or similar)/eval, but I cannot recommend them because Storable’s format is Perl version dependent, and eval is unsafe because it executes arbitrary code. As of 2012, the parsing counter-part Data::Undump has not progressed very far yet. I also cannot recommend using XML because it does not map Perl data types well, and there exists multiple competing/incompatible schemas how to translate between XML and data.

Code examples (tested):

use JSON::XS qw(encode_json decode_json);
use File::Slurp qw(read_file write_file);
my %hash;
{
    my $json = encode_json \%hash;
    write_file('dump.json', { binmode => ':raw' }, $json);
}
{
    my $json = read_file('dump.json', { binmode => ':raw' });
    %hash = %{ decode_json $json };
}

use YAML::XS qw(Load Dump);
use File::Slurp qw(read_file write_file);
my %hash;
{
    my $yaml = Dump \%hash;
    write_file('dump.yml', { binmode => ':raw' }, $yaml);
}
{
    my $yaml = read_file('dump.yml', { binmode => ':raw' });
    %hash = %{ Load $yaml };
}

The next step up from here is object persistence.

Also read: Serializers for Perl: when to use what

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