void from_backend(int is_stderr, char *data, int len)
int from_backend(int is_stderr, char *data, int len)
void from_backend(int is_stderr, char *data, int len){    int pos;    DWORD ret;    HANDLE h = (is_stderr ? errhandle : outhandle);    pos = 0;    while (pos < len) {	if (!WriteFile(h, data + pos, len - pos, &ret, NULL))	    return;		       /* give up in panic */	pos += ret;    }}