diff --git a/Makefile b/Makefile
index cc76595..8bb38f0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,13 @@
-TESTS=test/input
+TESTS=test/input test/exec
 
 tests: $(TESTS)
 	for i in $(TESTS); do ./$$i -v; done
 
+TEST_EXEC=test/exec.o exec.o
+test/exec: $(TEST_EXEC)
+	$(CC) -Wall $(TEST_EXEC) -o test/exec
 TEST_INPUT=test/input.o input.o
 test/input: $(TEST_INPUT)
 	$(CC) -Wall $(TEST_INPUT) -o test/input
 .c.o:
-	$(CC) -std=c89 -Wall -c $< -o $@
+	$(CC) -g -std=c89 -Wall -c $< -o $@
diff --git a/exec.c b/exec.c
index d561b64..f498ac5 100644
--- a/exec.c
+++ b/exec.c
@@ -15,13 +15,13 @@ int strcmp(const char *s1, const char *s2) {
 # include <string.h>
 #endif
 
-struct libscomm_cmd *hg_bsearch(const char *name, struct libscomm_cmd_store *cmds) {
+struct libscomm_cmd *hg_bsearch(const char *name, const struct libscomm_cmd_store *cmds) {
 	size_t lower = 0, upper = cmds->len-1;
 	size_t i;
 	int rel;
 
-	while (upper <= lower) {
-		i = upper-lower/2;
+	while (upper >= lower) {
+		i = (upper - lower)/2 + lower;
 		rel = strcmp(name, cmds->arr[i].name);
 		/* x > cmds[i] */
 		if (rel > 0)
@@ -35,10 +35,10 @@ struct libscomm_cmd *hg_bsearch(const char *name, struct libscomm_cmd_store *cmd
 	return NULL;
 }
 
-int libscomm_exec(const char *name, struct libscomm_cmd_store *cmds, struct libscomm_line *ln) {
+int libscomm_exec(const struct libscomm_cmd_store *cmds, struct libscomm_line *ln) {
 	struct libscomm_cmd *cmd;
 
-	cmd = hg_bsearch(name, cmds);
+	cmd = hg_bsearch(ln->buf[ln->name], cmds);
 	if (!cmd)
 		return LIBSCOMM_NOT_FOUND;
 	return cmd->exec(ln);
diff --git a/exec.h b/exec.h
index 6ee672c..0069014 100644
--- a/exec.h
+++ b/exec.h
@@ -16,4 +16,8 @@ struct libscomm_cmd_store {
 	size_t len;
 };
 
-#define libscomm_mkcmds(l) {l, sizeof(l) / sizeof(l[0])}
+#if defined(__STDC_VERSION__)
+#define libscomm_mkcmds(...) {(struct libscomm_cmd []){__VA_ARGS__}, \
+	sizeof((struct libscomm_cmd []){__VA_ARGS__}) / sizeof((struct libscomm_cmd []){__VA_ARGS__}[0])}
+#endif
+int libscomm_exec(const struct libscomm_cmd_store *cmds, struct libscomm_line *ln);