#perl

Functional logfile processing. Check logs for a task running on multiple nodes at once, first with Perl’s diamond operator and hashes, then in Haskell.

How Unix represents file permissions. Why stat reports 33188 for a 644 file: st_mode bit fields, file-type bits, octal, and masking with 07777 in Perl.

Diagnosing a strange error from Net::OpenID::Consumer in a Mojolicious app: tracing naive_verify_failed_network to a missing IO::Socket::SSL dependency.

Using split versus pattern matching. Pulling integers from a line in Perl: stray carriage returns, Randal Schwartz’s rule of thumb, and named captures.

Swapping libraries at compile time. Why a Perl use inside an if always loads the module, and how BEGIN blocks with require or eval do the job properly.

Scrape a command’s output in a few lines of Perl: load AIX vmstat values into a hash with a piped open and split, then with a one-line regex and reverse.

A complete, cross-referenced desk reference to Perl’s core syntax, functions, and modules for experienced developers. I was its technical editor.

Paul Robichaux’s sysadmin’s guide to maintaining, monitoring, and updating the Windows 2000 Registry. I wrote its “Programming with Perl” chapter.

Time killer in Perl/Tk. A Perl Journal article that builds a Pyramid-style solitaire game step by step: rules, Fisher-Yates shuffle, layout, and moves.

Tutorial on using Perl to create utilities and CGI webapps such as forms and shopping carts. I was technical editor of the 1999 first edition.

An alternative to using hashes to implement Perl objects. My yapc99 talk at Carnegie Mellon, attended by Larry Wall, later a Perl Journal article.

Most people build objects out of hashes. Here’s why you shouldn’t. A Perl Journal article on array-based objects: speed, space, typos, and tradeoffs.