Another "war story" here -- not a question, but something worth passing on: A previous client of mine had some Summit and Zeiss precision measuring (i.e. metrology) machines, and about 6,000 programs to perform measurements on the various parts this company manufactured. They were in the process of migrating network operating systems (from Novell to Microsoft), and thus, had to change the hardcoded drive mappings in these files. All 6,000 of them.

No way was I going to do this manually. (Laziness, y'know?) I could write a perl script to perform a search-and-replace mission. And I did. But there was another problem: the script wasn't finding the filepaths based on the regex I wrote. So I then did a hexdump on a couple of these files. That's when I discovered the files were in binary format, but the filepaths were plain-text. What was I to do? RTFD. I came across the binmode command, which enabled me to open up files in binary format. So I tried it. And it worked -- it finally matched the regex, and replaced the old drive mapping with the new path.

binmode FILEHANDLE;
[download]

But there were still some paths that didn't get converted. These were mostly for external shape definition files, and comprised about 10% of the total set of programs. So I called the vendor to see if they had a product to do what we wanted to do. And the vendor told me "it couldn't be done". I knew otherwise, but I wasn't going to tell the vendor that they were wrong.

Bottom line: Using binmode, Perl can be used to edit binary files. But Be Careful How You Use It!