#include <unistd.h> #include <errno.h> #include "file.h" int getscreensize(int fd, int *rows, int *cols) { struct file_info *fp = &__file_info[fd]; if (fd >= NFILES || !fp->iop) { errno = EBADF; return -1; } *rows = fp->o.rows; *cols = fp->o.cols; if (!*rows || !*cols) { errno = ENOTTY; return -1; } return 0; }