added trivial test for fts routines

lib/libc/tests/gen/ftstest.c

@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <fts.h>
+#include <assert.h>
+
+int main (int argc, char **argv) {
+
+	FTS *ftsp;
+	FTSENT *entp;
+	int options;
+
+	if (argc < 2) {
+		printf("usage: %s dirname\n", argv[0]);
+		exit(1);
+	}
+	options = FTS_NOCHDIR | FTS_NOSTAT;
+	ftsp = fts_open(&argv[1], options, NULL);
+	if (ftsp == NULL) {
+		printf("fts_open failed\n");
+		exit(1);
+	}
+	
+	while ((entp = fts_read(ftsp)) != NULL) {
+		assert(entp->fts_name != NULL);
+		printf("%s\n", entp->fts_name);
+	}
+	if (errno) {
+		perror("fts_read return code");
+	}
+
+	options = fts_close(ftsp);
+	printf("fts_close returned %d\n", options);
+	return 0;
+}