_IOLBF
setvbuf(stdout, NULL, _IOLBF, 0);
#define setlinebuf(a) (setvbuf((a), NULL, _IOLBF, 0))
setvbuf(stdout, NULL, _IOLBF, 0);
setvbuf(infile, NULL, _IOLBF, 0);
setvbuf(stdout, NULL, _IOLBF, 0);
setvbuf(out, NULL, _IOLBF, 0);
setvbuf(out, NULL, _IOLBF, 0);
return (setvbuf(fp, (char *)NULL, _IOLBF, (size_t)0));
if (mode == _IOLBF)
if ((mode != _IOFBF && mode != _IOLBF) || size > INT_MAX)
ATF_REQUIRE(setvbuf(f, buf, _IOLBF, BUFSIZE) == 0);
ATF_REQUIRE(setvbuf(f, buf, _IOLBF, BUFSIZE) == 0);
mode = _IOLBF;
setvbuf(stdout, (char *)0, _IOLBF, 0); /* line buffered stdout */
setvbuf(stdout, NULL, _IOLBF, 0);
setvbuf(stderr, NULL, _IOLBF, 0);
if(setvbuf(stdout, NULL, _IOLBF, 0) != 0)
setvbuf(stdout, NULL, _IOLBF, BUFSIZ);