Decipher binary format of file

I have a binary file to w开发者_运维百科hich I'm trying to write however I dont have the file format specification nor have found it using google, I've been looking at the file using a hex editor but so far has only give me a headache, is there a better way to decipher the format of the file so that I can append data to it?

File carving tools such as scalpel won't really help here. They're made for extracting files with known header and/or footer signatures from a memory dump or some larger, composite file.

For your scenario, I would recommend a hex editor with templating capability, like the 010 Editor. This will allow you to name and annotate "fields" in the binary as you learn more about what each part of the file does. Unfortunately, the process of finding out what each field does is mostly manual. As a methodology, just start playing with it. Change some values in your current binary and see what happens. Expect to spend significant time on it, but also enjoy the process!

you may want to search it with a open source forensic application like foremost or scalpel. They will do most of the grunt work for you, you just likely wont learn anything.