diff --git a/HISTORY b/HISTORY
index e36c11f..9c2489e 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,10 +1,11 @@
 
-Version 1.40  2018-08-24
+Version 1.40  2018-08-27
   * add function conn_pool_parse_server_info and conn_pool_load_server_info
   * support directive: #@add_annotation, for example:
     #@add_annotation CONFIG_GET /usr/lib/libshmcache.so /etc/libshmcache.conf
   * add function fc_split_string and fc_match_delim
   * add json_parser.[hc] for parse json array and map
+  * add function fc_strdup
 
 Version 1.39  2018-07-31
   * add #@function REPLACE_VARS
diff --git a/src/shared_func.c b/src/shared_func.c
index 4aa3ae1..763415e 100644
--- a/src/shared_func.c
+++ b/src/shared_func.c
@@ -2716,3 +2716,22 @@ bool ends_with(const char *str, const char *needle)
 
     return memcmp(str + start_offset, needle, needle_len) == 0;
 }
+
+char *fc_strdup(const char *str, const int len)
+{
+    char *output;
+
+    output = (char *)malloc(len + 1);
+    if (output == NULL) {
+        logError("file: "__FILE__", line: %d, "
+                "malloc %d bytes fail",
+                __LINE__, len + 1);
+        return NULL;
+    }
+
+    if (len > 0) {
+        memcpy(output, str, len);
+    }
+    *(output + len) = '\0';
+    return output;
+}
diff --git a/src/shared_func.h b/src/shared_func.h
index 81423d2..220c8d1 100644
--- a/src/shared_func.h
+++ b/src/shared_func.h
@@ -791,6 +791,14 @@ bool starts_with(const char *str, const char *needle);
 */
 bool ends_with(const char *str, const char *needle);
 
+/** strdup
+ *  parameters:
+ *  	str: the string to duplicate
+ *      len: the length of string
+ *  return: the duplicated string, NULL for fail
+*/
+char *fc_strdup(const char *str, const int len);
+
 #ifdef __cplusplus
 }
 #endif