Set socket to non-blocking in linux

Use the following method to set the socket to non-blocking mode:
Int flags = fcntl (socket, f_getfl, 0 );
Fcntl (socket, f_setfl, flags | o_nonblock );

You can use the non-blocking setting back to block

Int flags = fcntl (socket, f_getfl, 0 );
Fcntl (socket, f_setfl, flags &~ O_nonblock );

Function Description: describes the features of a file based on its description.

Usage:
Int fcntl (int fd, int cmd );
Int fcntl (int fd, int cmd, long Arg );
Int fcntl (int fd, int cmd, struct flock * Lock );

Parameters:
FD: file description.
CMD: Operation Command.
Arg: parameters used by commands.
Lock: Same as above.