man ndelay_on () - put file descriptor in non-blocking mode
NAME
ndelay_on - put file descriptor in non-blocking mode
SYNTAX
#include <ndelay.h>
extern int ndelay_on(int fd);
DESCRIPTION
ndelay_on puts a file descriptor in non-blocking mode. Reading from and writing to non-blocking network sockets, FIFOs or device files will return immediately, even if not as many bytes have been processed as were specified.
If an error occurred, ndelay_on will return nonzero and set errno accordingly.
SEE ALSO
fcntl(2), ndelay_off(3)