diff --git a/src/str.h b/src/str.h
new file mode 100644
index 0000000..4737ad2
--- /dev/null
+++ b/src/str.h
@@ -0,0 +1,8 @@
+#ifndef _STR_H
+#define _STR_H
+void string_concat(char *dst,char *src);
+void string_copy(char* dst, char *src, int length);
+void string_rconcat(char *dst,char *prefix);
+int string_cmp(char* s1, char *s2, int maxlength);
+int string_length(char* s);
+#endif