if(fwrite(buf, 1, len, arg) != len) return 0;
if(fwrite(buf, 1, len, arg) != (unsigned int)len) return 0;
int send_fp_chars(void *arg, const void *buf, int len){	if(!arg) return 1;	if(fwrite(buf, 1, len, arg) != len) return 0;	return 1;}