Saving Data Structures

If you want to save your data structures for use by another program later, there are many ways to do it. The easiest way is to use Perl's Data::Dumper module, which turns a (possibly self-referential) data structure into a string that can be saved externally and later reconstituted with eval or do.

use Data::Dumper; $Data::Dumper::Purity = 1; # since %TV is self-referential open (FILE, "> tvinfo.perldata") or die "can't open tvinfo: $!";
print FILE Data::Dumper->Dump([\%TV], ['*TV']); close FILE or die "can't close tvinfo: $!";

open (FILE, "< tvinfo.perldata") or die "can't open tvinfo: $!"; undef $/; # read in file all at once eval <FILE>; # recreate %TV die "can't recreate tv data from tvinfo.perldata: $@" if $@; close FILE or die "can't close tvinfo: $!";
print $TV{simpsons}{members}[2]{age};

do "tvinfo.perldata" or die "can't recreate tvinfo: $! $@";
print $TV{simpsons}{members}[2]{age};