The Perl Debugger Resources (Issue 49)
Programming Perl, Second Edition, Larry Wall, Tom Christiansen & Randal L. Schwartz, O'Reilly & Associates, Inc., September 1996.
The Perl 5 debugger man page, http://www.perl.org/CPAN/doc/manual/html/pod/perldebug.html.
All listings referred to in this article are available by anonymous download in the file ftp://ftp.ssc.com/pub/lj/listings/issue49/2484.tgz. Also included in the tgz file is a CGI program for you to debug.
Doubly Linked Lists Resources (Issue 49)
All listings referred to in this article, including the DLL package, are available by anonymous download in the file ftp://ftp.ssc.com/pub/lj/listings/issue49/2693.tgz.