c++ file descriptor (sockets) isopen()?

Question

In C++, is there a way to check if a file descriptor is still open, long after it was initially opened?

score 3 · Accepted Answer · edited May 23 '17 at 11:47

3

You can use fcntl with the F_GETFL to get if the fd is valid or not.

edited May 23 '17 at 11:47

Community

answered Apr 12 '11 at 12:42

Milan

If the file descriptor was closed, fcntl will fail. (So it doesn't matter whether you use F_GETFL or any other command.) – William Pursell May 12 '11 at 14:25

score 2 · Answer 2 · answered Apr 12 '11 at 12:52

2

fstat is the most portable way I can think of.

If you tell us what platform, we may be able to suggest something better for your particular situation.

answered Apr 12 '11 at 12:52

Ben Voigt

2 Answers2