Finding something after a search term

How can you determine if there are more bytes to a file after a certain string? I want to parse a file, find a certain combination of values, and then see if that's the end of the file or not. What will happen next depends on whether that's the end or not. Any ideas?

>>7
I'm the OP, and believe it or not, I'm programming for a personal project, not a class assignment. Just because someone isn't an EXPERT PROGRAMMER doesn't mean everything they program is for homework.
>>8
You didn't make this thread, so why answer for me?