Depends on whether we are talking about command-line interface.

1. If it is command-line interface, yes, Perl is a good candidate. The first thing coming up in my mind is its powerful regexp, so you can easily parse user input (command).
2. If this is a programming interface (API's). Better just follow the majority of your users. If most of guys in your company use c, write it in c, if they use Java, write it in Java, obviously write it in Perl, if they use Perl. I did a tool before (a set of API's other call to write their own testing script), I created three versions, Perl, c and Java, as we had big enough user bases for all three languages.