posix-io/isatty.c

#include <windows.h>
#include <errno.h>

int isatty(int fd) {
	if(fd == -1) {
		errno = EBADF;
		return 0;
	}
	if(GetFileSize((void *)fd, NULL) == 0xffffffff) {
		if(GetLastError() == ERROR_INVALID_FUNCTION) {
			SetLastError(0);
			return 1;
		}
		return 0;
	}
	errno = ENOTTY;
	return 0;
}