"Although optimized for scanning text, Perl can also deal with binary data..."

I am filtering the output of an app that generates text followed by PDF by using a regular expression substition that gets rid of the text. (The "app" is actually several components piped together - it is convenient to just let the text output stay as long as I can remove it at the end). This seems to work, but wondered if there might problems that I just haven't run into yet. <update> I should give a little more detail:

I am capturing all the output in a scalar and then doing several multi-line RE substitutions on it using the "s" flag.