I was modifying one of our processes today and I came across some bizarre behavior. Essentially, the process reads in a flat configuration file which contains data like 
stored_proc_list => [ 'sproc1', 'sproc2', 'sproc3' ]
update_stats_xref => { 'sproc2' => 'update_table2' }
logfile => somefile.txt

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and converts them into Perl variables (array ref, hash ref, and scalar respectively) using an eval statement. When I tried to update the code to allow for scalar references (which would immediately get converted into a scalar), it started to core dump on me. I have included the offensive code below, stripped down to what appears to be its barest elements. Essentially I have a string, which gets turned into a Scalar reference when I eval it, which I then try to assign back into the same value. If I do a Scalar assignment, it blows up. If I do a list assignment, it works just fine.

I was hoping that someone out there can explain this behavior to me. I have already found a working solution, but I was curious as to why it works (or doesn't) the way it works. Note: I have tried this on both NT 4.0 (which I where I do most of my development :< ) and on AIX. 
my $temp_value = q(\'/Path/to/log.txt');
my $value = eval $temp_value;  

# This one results in no value for $value and coredumps
$value = $$value;
print "New \$value = $value\n";

# This one does what I want it to do
( $value ) = ( $$value );
print "New \$value = $value\n";

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Thanks for any insight,
Mike
mppennucci@delinvest.com

In reply to Bizarre References Question by mpennucci

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