write and read from a binary file

[Maestro]

Hi!

A write out data to a binary file and later I want to read from it.
The problem is, when I use fread, it finds EOF somewhere in the middle of the file. I want to read int32 values when it occurs.

I think the hexa code of EOF is 04 and I had int32 i=4 data. Later I added 100 to every int at write and I subtracted 100, when I readed it, but the same thing happend.

How should I avoid that? Overstep it with fseek or what?

Thanx

[Bob Davis]

Where are you getting this hex code 04 from? If you're using fread, you can just watch the returned value, which indicates how many bytes were read. If it is less than 4, you're probably at EOF, or a file error occurred. You can use feof() to find out which for sure.

Is there any reason why you couldn't use iostreams to accomplish the same thing? Reading integers from a binary file is a snap using ifstream, and the class has all of the functions that you're probably used to in your "C" standard library. I understand that whatever system you're coding for might not support C++, but if possible I would consider it.

[Maestro]

fread() returns 0 and feof() returns non zero. I have to use standard C.

[fellowDeveloper]

What type of access are you using when you open the file?

file = fopen("filename", "rb") should do the trick.

[Maestro]

Ohh, that's it!

Thanx