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