How do I read back in the output of Data::Dumper?

Question

Let\'s say I have a text file created using Data::Dumper, along the lines of:

my $x = [ { foo => \'bar\', asdf => undef }, 0, -4, [ [] ] ];

Answer 1

If you want to stay with something easy and human-readable, simply use the Data::Dump module instead of Data::Dumper. Basically, it is Data::Dumper done right -- it produces valid Perl expressions ready for assignment, without creating all those weird $VAR1, $VAR2 etc. variables.

Then, if your code looks like:

my $x = [ { foo => 'bar', asdf => undef }, 0, -4, [ [] ] ];

Save it using:

use Data::Dump "pp";
open F, ">dump.txt";
print F pp($x);

This produces a file dump.txt that looks like (on my PC at least):

[{ asdf => undef, foo => "bar" }, 0, -4, [[]]]

Load it using:

open F, "dump.txt";
my $vars;
{ local $/ = undef; $vars = ; }
my $x = eval $vars;

Note that

1. If you're bothering to put the assignment to $/ in its own block, you should use local to ensure it's value is actually restored at the end of the block; and
2. The result of eval() needs to be assigned to $x.