porting ioctl() calls from unix to linux, error with FIONBIO

Question

i want to use ioctl() to get the number of bytes ready to be read

the way I did it is:

mysocket=socket(....);
ioctl(mysocket, FIONBIO, &zero);            


        

Answer 1

Have you tried including sys/ioctl.h?

This code works for me:

#include <sys/ioctl.h>
#include <stdio.h>

int main() {
    printf("FIONBIO value %d\n", FIONBIO);
}

When I execute grep -R FIONBIO /usr/include, it's found here:

/usr/include/asm-generic/ioctls.h:#define FIONBIO 0x5421