__sfvwrite
r = __sfvwrite(fp, &uio);
if (__sfvwrite(fp, &uio)) {
extern int __sfvwrite(FILE *, struct __suio *);
if (__sfvwrite(fp, &uio) != 0)
r = __sfvwrite(stdout, &uio);
r = __sfvwrite(fp, &uio);
return __sfvwrite(fp, &uio) != EOF ? (wint_t)wc : END_OF_FILE;
err = __sfvwrite(fp, uio);