#include <sys/ioctl.h>
#include <stdio.h>
#include <unistd.h>
int main (int argc, char **argv)
{
struct winsize w;
ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
printf ("lines %d
", w.ws_row);
printf ("columns %d
", w.ws_col);
return 0; // make sure your main returns int
}