# slightly modified from Storable docs
use strict;
use warnings;
use Safe;
use Storable qw(freeze thaw);

my $safe = Safe->new();
$safe->permit(qw(:default require));

local $Storable::Deparse = 1;
local $Storable::Eval = sub { $safe->reval($_[0]) };
my $serialized = freeze(sub { return 'hello world' });
my $code = thaw($serialized);
print $code->(), "\n";
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jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

You can use B::Deparse to create a string from a coderef that you can then eval back to the coderef again.

The latest version of Data::Dumper can do this for you. Take a look at the $Data::Dumper::Deparse switch.

Wow,


that was fast,
thanks,
Carl

Hm, well writing a sub to a file works, but how can I use it
after I've re-read it?

B::Deparse shows this: eval "sub func $ret". But this doesn't work.
Either nothing happans or I get a failor, that the sub is not predeclared :-/

#! /usr/bin/perl
# write-read-execute code

my %hash = ();

# btw, all of a sudden there is a syntax error near: $hash{
# I have no idea why (can't test this, while simular code works?)
$hash{'code'} = sub { print "Hi Guy - Hello Fellow!\n" };
&$hash{'code'}();

my $string = toStr($hash{'code'};
$hash{'code'} = toCode( split(/\n/, $string) );

# this should work (as before saved):
&$hash{'code'}();

# the two subs
sub toStr { 
    use B::Deparse;
    my $ret .= $deparse->coderef2text( shift )."\n";
    $ret .= B::Deparse->new("-p", "-sC")->coderef2text( shift )."\n";
    return $ret;
}
sub toCode {
    my $ret;
    while ( @_ )
    {
        $ret .= (shift)."\n"; # "\n" was eliminated by split
    }
    # NOW MAKE $ret been executed:
    # This is the examlpe of B:Deparse:
    eval "sub func $ret"; # but nothing happens

    # this causes this mistake:
    # Undefined subroutine &sub
    &{$ret};

    # this should be given back:
    return $ret;
}
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Am I doing s.th. wrong?
Thanks,
Carl

OOPS, please be aware of two minor bugs in sub toStr,
here is the corrected code (but all other mistaks are still there):

#! /usr/bin/perl
# write-read-execute code

my %hash = ();

# btw, all of a sudden there is a syntax error near: $hash{
# I have no idea why (can't test this, while simular code works?)
$hash{'code'} = sub { print "Hi Guy - Hello Fellow!\n" };
&$hash{'code'}();

my $string = toStr($hash{'code'};
$hash{'code'} = toCode( split(/\n/, $string) );

# this should work (as before saved):
&$hash{'code'}();

# the two subs
sub toStr { 
    use B::Deparse;
    return B::Deparse->new("-p", "-sC")->coderef2text( shift )."\n";
}

sub toCode {
    my $ret;
    while ( @_ )
    {
        $ret .= (shift)."\n"; # "\n" was eliminated by split
    }
    # NOW MAKE $ret been executed:
    # This is the examlpe of B:Deparse:
    eval "sub func $ret"; # but nothing happens

    # this causes this mistake:
    # Undefined subroutine &sub
    &{$ret};

    # this should be given back:
    return $ret;
}
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