I took a look around Amazon, and I'm almost certain that his recommendation was "Minimal Perl: For Unix and Linux People", by Tim Maher. I recall the title emphasizing least or another synonymous adjective (not including 'basic' or other frequently used terms for books geared towards beginners). Judging by user reviews, the book's scope seems in-line with what the interviewer described, but with a lot of emphasis on Perl one-liners. Debating whether I should order a copy, or just finally finish an O'Reilly book and force myself to write a script a day to stay familiar with the language.