Definition of interpreter: "An interpreter translates high-level instructions into an intermediate form, which it then executes. ..."

By that definition, your bash script most definitly is an interpreter. And, so is Perl.

Another definition I saw "a program that translates and executes source language statements one line at a time". By that definition, neither your script nor Perl is an interpreter. (That definition was also found here and here.)

*shrugs* The devil's in the details, I guess. I take a black-box approach, which is supported by webopedia. You are taking a white-box approach, supported by hyperdictionary, computerdictionary, and thefreedictionary. If we were to vote on it, you'd Kerry my Edwards, I guess. *grins*