I am very grateful to Dr. Robert McDowell for uncovering a presentation problem in all of the Perl scripts that I've posted in prior blogs.
When the blog software encounters a Perl get-file command (<FILENAME>), it misinterprts the Perl expression as an HTML tag and suppresses its visibility.
Consequently, all of the Perl scripts that called for a line of a file (i.e., most of my posted Perl files) had a missing filehandle. I've gone back through all of the old posts and have substituted HTML bracket expressions (<, >) where appropriate, and I think this should have fixed the problem.
I apologize for any inconvenience this may have causes.
- Jules Berman