Opariti

Hi,
I'd like to have your expertise on writing in random mode - after setting the current pointer with fseek - into an existing binary file. I'm getting somehow confused with a bunch of options for fopen_s, including an "R" (for random), and a "c" to force "hard flushing" into the disk (bypassing the system's buffers), that I read about for the first time. What would be the right function to write - so that to avoid writing byte by byte?
Thanks!

Salem

Just a regular fopen() with a mode of "r+b" should suffice.

Then seek to where you want to write, then fwrite() as much data as you please.

Call fflush() if you switch back to reading the file.

> I'm getting somehow confused with a bunch of options for fopen_s, including an "R" (for random), and a "c" to force "hard flushing" into the disk
All of which is non-portable.

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Opariti

I've tested the optimal configuration: fopen() with "wbc" mode and fwrite() as per the manual. Good performance since fseek() does automatically fflush() prior to any field pointer positionning into the file. Thanks!