usend
ATF_REQUIRE(usend(s, "foo", sizeof("foo")) == sizeof("foo"));
ATF_REQUIRE(usend(s, "foo", sizeof("foo")) == sizeof("foo"));
ATF_REQUIRE(usend(s, CHUNK1, LEN(CHUNK1)) == LEN(CHUNK1));
ATF_REQUIRE(usend(s, CHUNK2, LEN(CHUNK2)) == LEN(CHUNK2));
ATF_REQUIRE(usend(s, "foo", sizeof("foo")) == sizeof("foo"));
ATF_REQUIRE(usend(s, "bar", sizeof("bar")) == sizeof("bar"));
ATF_REQUIRE(usend(s, &header, sizeof(header)) == sizeof(header));
ATF_REQUIRE(usend(s, buf, len) == (ssize_t)len);