initial import
diff --git a/utils.c b/utils.c
new file mode 100644
index 0000000..882ef2d
--- /dev/null
+++ b/utils.c
@@ -0,0 +1,68 @@
+/* Capstone Disassembler Engine */
+/* By Nguyen Anh Quynh <aquynh@gmail.com>, 2013> */
+
+#include <string.h>
+
+#include "utils.h"
+
+// check to see if a string exists in a list of string ...
+bool str_in_list(char **list, char *s)
+{
+ char **l;
+
+ for(l = list; *l; l++)
+ if (!strcasecmp(*l, s))
+ return true;
+
+ return false;
+}
+
+// binary searching
+int insn_find(insn_map *m, unsigned int max, unsigned int id)
+{
+ unsigned int i, begin, end;
+
+ begin = 0;
+ end = max;
+
+ while(begin <= end) {
+ i = (begin + end) / 2;
+ if (id == m[i].id)
+ return i;
+ else if (id < m[i].id)
+ end = i - 1;
+ else
+ begin = i + 1;
+ }
+
+ // found nothing
+ return -1;
+}
+
+int name2id(name_map* map, int max, char *name)
+{
+ int i;
+
+ for (i = 0; i < max; i++) {
+ if (!strcasecmp(map[i].name, name)) {
+ return map[i].id;
+ }
+ }
+
+ // nothing match
+ return -1;
+}
+
+unsigned int insn_reverse_id(insn_map *insns, unsigned int max, unsigned int id)
+{
+ unsigned int i;
+
+ for (i = 0; i < max; i++) {
+ if (id == insns[i].mapid)
+ return insns[i].id;
+ }
+
+ // found nothing
+ return 0;
+}
+