diff --git a/tinyweb.c b/tinyweb.c
index 17bbfa0..e889906 100644
--- a/tinyweb.c
+++ b/tinyweb.c
@@ -107,17 +107,18 @@ void tw_send_data(uv_stream_t* client, const void* data, size_t len, char need_c
 
 //获取头部 SetCookie 字段值
 //setCookie: 缓存区(至少 110+strlen(domain)=strlen(path) )，外部传入
+//ckLen: set_cookie的长度
 //expires: 多少秒后过期
 //domain: Domain, 可以是 heads->host，外部传入
 //path: Path, 可以是 heads->path，外部传入
-void tw_make_cookie(char* set_cookie,int expires,char* domain,char* path)
+void tw_make_cookie(char* set_cookie,int ckLen,int expires,char* domain,char* path)
 {
 	char val[30];
 	char szDate[30];
-	getGmtTime(szDate,expires);
+	getGmtTime(szDate,30,expires);
 	path == NULL ? path = "/" : 0;
 	snprintf(val, 100, "Tiny%lld", str2stmp(NULL));
-	snprintf(set_cookie, sizeof(set_cookie), "SetCookie: TINY_SSID=%s; Expires=%s; Path=%s; Domain=%s;\r\n"
+	snprintf(set_cookie, ckLen, "SetCookie: TINY_SSID=%s; Expires=%s; Path=%s; Domain=%s;\r\n"
 		, val, szDate, path, domain);
 }
 
@@ -167,7 +168,7 @@ char* tw_format_http_respone(uv_stream_t* client, const char* status, const char
 	size_t totalsize, header_size;
 	char* respone;
 	char szDate[30];
-	getGmtTime(szDate,0);
+	getGmtTime(szDate,30,0);
 	ext_heads == NULL ? ext_heads = "" : 0;
 	tw_config* tw_conf = (tw_config*)(client->loop->data);
 	if (content_length == 0 || content_length == (size_t)-1)
@@ -199,7 +200,7 @@ static void tw_301_Moved(uv_stream_t* client, tw_reqHeads* heads, const char* ex
 	size_t len = 76 + strlen(heads->path);
 	char buffer[10245];
 	char szDate[30];
-	getGmtTime(szDate,0);
+	getGmtTime(szDate,30,0);
 	tw_config* tw_conf = (tw_config*)(client->loop->data);
 	snprintf(buffer, sizeof(buffer), "HTTP/1.1 301 Moved Permanently\r\nDate: %s\r\n"
 		"Server: TinyWeb\r\nLocation: http://%s%s/%s%s\r\nConnection: close\r\n"
@@ -250,7 +251,7 @@ static char tw_http_send_file(uv_stream_t* client, const char* content_type, con
 			tw_404_not_found(client, heads->path, ext_heads);
 			return 0;
 		}
-		getGmtTime(szDate,0);
+		getGmtTime(szDate,30,0);
 		respone = (char*)malloc(300 + 1);
 		int respone_size;
 		if (heads->Range_frm == 0) //200 OK
diff --git a/tinyweb.h b/tinyweb.h
index 487f1d2..b7c61d3 100644
--- a/tinyweb.h
+++ b/tinyweb.h
@@ -139,10 +139,11 @@ void tinyweb_stop(uv_loop_t* loop);
 
 //获取头部 SetCookie 字段值
 //set_cookie: 缓存区(至少 110+strlen(domain)=strlen(path) )，外部传入
+//ckLen: set_cookie的长度
 //expires: 多少秒后过期
 //domain: Domain, 可以是 heads->host，外部传入
 //path: Path, 可以是 heads->path，外部传入
-void tw_make_cookie(char* set_cookie, int expires, char* domain, char* path);
+void tw_make_cookie(char* set_cookie, int ckLen, int expires, char* domain, char* path);
 
 //处理客户端请求
 //invoked by tinyweb when GET request comes in
diff --git a/tools.c b/tools.c
index 0cda029..4e49a41 100644
--- a/tools.c
+++ b/tools.c
@@ -239,7 +239,7 @@ char isDir(const char* path)
 	return (fd.name[0] && (fd.attrib & FILE_ATTRIBUTE_DIRECTORY));
 }
 
-//列表目录
+//返回列表目录Json字符串,need free the return
 char* listDir(const char* fullpath, const char* reqPath)
 {
 	int fnum = 0;
@@ -375,7 +375,7 @@ char isFile(const char* path)
 	return 0;
 }
 
-//列表目录
+//返回列表目录Json字符串,need free the return
 char* listDir(const char* fullpath, const char* reqPath)
 {
 	int fnum = 0;
@@ -1462,15 +1462,17 @@ inline int day_of_year(int y, int m, int d)
 
 //获取格林制（GMT）时间: "Wed, 18 Jul 2018 06:02:42 GMT"
 //szDate: 存放GMT时间的缓存区(至少 char[30])，外部传入
+//szLen: szDate的长度大小
 //addSecond: 当前时间加上多少秒
-void getGmtTime(char* szDate,int addSecond)
+char* getGmtTime(char* szDate,int szLen,int addSecond)
 {
 	time_t rawTime;
 	struct tm* timeInfo;
 	time(&rawTime);
 	rawTime += addSecond;
 	timeInfo = gmtime(&rawTime);
-	strftime(szDate, sizeof(szDate), "%a, %d %b %Y %H:%M:%S GMT", timeInfo);
+	strftime(szDate, szLen, "%a, %d %b %Y %H:%M:%S GMT", timeInfo);
+	return szDate;
 }
 
 //字符串转换成时间戳(秒),字符串格式为:"2016-08-03 06:56:36"
diff --git a/tools.h b/tools.h
index 4c55376..aa8ece1 100644
--- a/tools.h
+++ b/tools.h
@@ -97,7 +97,8 @@ extern "C" {
 	//是否目录(1:是目录  0;非目录/不存在)
 	char isDir(const char* path);
 
-	//网页，列表目录,need free the return
+	//返回列表目录Json字符串,need free the return
+	//{"path":"/","files":[{"name":"file.txt","mtime":"2014-04-18 23:24:05","size":463,"type":"F"}]}
 	char* listDir(const char* fullpath, const char* reqPath);
 
 	//-----------------------------------------------------------------------------------编码转换  win/unix
@@ -228,8 +229,9 @@ extern "C" {
 
 	//获取格林制（GMT）时间: "Wed, 18 Jul 2018 06:02:42 GMT"
 	//szDate: 存放GMT时间的缓存区(至少 char[30])，外部传入
+	//szLen: szDate的长度大小
 	//addSecond: 当前时间加上多少秒
-	void getGmtTime(char* szDate, int addSecond);
+	char* getGmtTime(char* szDate, int szLen, int addSecond);
 
 	//字符串转换成时间戳(秒),字符串格式为:"2016-08-03 06:56:36"
 	llong str2stmp(const char *strTime);