Question

I am wondering if you can : lock only a line or a single character in a file in linux and the rest of the file should remain accessible for other processes?
I received a task regarding simulating transaction on a file with c/c++ under linux .
Please give me an answer and if this answer is yes ,give me some links from where i could take a peek to make this task.

Thanks,
Madicemickael

Answer 1

Yes, this is possible.

The Unix way to do this is via fcntl or lockf.
Whatever you choose, make sure to use only it and not mix the two. Have a look at this question (with answer) about it: fcntl, lockf, which is better to use for file locking?.

If you can, have a look at section 14.3 in Advanced Programming in the UNIX Environment.