How do I find the data segment of Mac OSX executable with Perl?

Question

I'm writing a tool in Perl that needs to scan for certain binary patterns inside an executable file on a Mac OSX. To avoid getting very many false positives, I want to restrict my search to the data/text segment of the executable, excluding the code segment and a few other things. How can I accomplish this?

Answer 1

How about using otool?

-t     Display the contents of the (__TEXT,__text) section.  
-d     Display the contents of the (__DATA,__data) section.

Answer 2

You should look at the ELF file format specification. It contains headers and tables that tell you exactly which segments live where. Parsing it is tedious but straightforward.