> These days if it's more than 5 lines of code, or if arbitrary filenames are involved I go straight to Perl or Python

Totally agreed. A shell script exceeding that's about 10 lines of code becomes so complex to read, interpret and improve that even though it may perform faster I would rather get the job done in a language that I can understand better when I come back to this 3 months later.

Although ... on that note I don't think I'd ever choose Perl ha ha.