he "test_pl_0ca9" could also be determined in advance - but it will change everytime you make a change to the C code in the script.

You can avoid that (the appending of hex characters to the name), by using the NAME => 'yourname' Inline option. It also make finding the generated C files easier when it comes to tracking down bugs.

Now if only there were an option that would prevent me from making fixes in the .c file instead of the .xs and then spending 10 minutes figuring out why nothing I do seems to change the error, and we (I) would be laughing.