What do you mean by "letting the script let me know what the input file is"?

Do you want to be able to specify the input file like:

[computer:~] codypendant% perl replaceids.pl names.txt
[download]

Or do you just want the program to tell you what it's doing, like:

[computer:~] codypendant% perl replaceids.pl names.txt
opening names.txt
doing the replacements
finished! take a look at names-replaced.txt
[download]

“Every bit of code is either naturally related to the problem at hand, or else it's an accidental side effect of the fact that you happened to solve the problem using a digital computer.”
M-J D

Cody, I have this workflow that will create multiple files over time as I get new pictures of the science fair. Thus, I'll have different files to process each time, so the first syntax you have would be what I would need. That is, I'll want to do this for names.txt, names2.txt, etc. Another feature that would help, since this starts as canned html with links (from iPhoto on the mac) would be to save the original names.txt file as a backup names.bak and have the modified file take the original name, names.txt. Then, no links would be broken in the html. With these changes, I'd have all I need. Thanks for your help. --cheers, Gordon