diff --git a/client.c b/client.c
index 53c0f0f..bafea34 100644
--- a/client.c
+++ b/client.c
@@ -187,7 +187,9 @@ int SendOpAndReceiveFile(const char * filename, struct sockaddr const * addr){
     close(sock);
     return ret;
 }
-
+//====
+//bench
+//====
 struct benchmark_data{
     bool benchmode;
     struct timespec begin;
@@ -207,22 +209,75 @@ void init_bench_data(){
         clock_getres(bench.clock_id,&bench.resolution);
     }
 }
-
-static size_t thread_number_option = 1;
-
+//====
+//simple queue
+//====
 typedef enum{
     From_CharArray,
     From_FileStream
 } queueing_method_t;
 
+typedef struct SimpleCharQueue{
+    queueing_method_t method;
+    const char ** filename_begin;
+    const char ** filename_end;
+    FILE * fs;
+} simple_queue_t;
+//
+// q have lifetime of arg b or arg e.
+// do not deallocate before queue closed.
+static bool init_queue_from_chararray(simple_queue_t * restrict q,const char ** b, const char ** e){
+    q->method = From_CharArray;
+    q->filename_begin = b;
+    q->filename_end = e;
+    return true;
+}
+//
+// q have lifetime of arg f.
+// do not close file f before queue closed.
+static bool init_queue_from_file(simple_queue_t * restrict q, FILE * f){
+    q->method = From_CharArray;
+    q->fs = f;
+    return true;
+}
+
+static const char * dequeue_from_simplecharqueue(simple_queue_t * restrict q,char * restrict buf, size_t size){
+    const char * filename;
+    if (q->method == From_CharArray){
+        if (__glibc_unlikely(q->filename_begin == q->filename_end)) {
+            return NULL;
+        }
+        filename = *(q->filename_begin++);
+    }
+    else{
+        //unsafe.
+        int t = fscanf(q->fs,"%s",buf);
+        if (__glibc_unlikely(t != 1)) {
+            return NULL;
+        }
+        filename = buf;
+    }
+    return filename;
+}
+//====
+//thread
+//====
 struct SimpleThreadGlobal{
     size_t thread_arr_size;
     pthread_t * thread_arr;
     pthread_mutex_t queueing_mutex;
-    queueing_method_t method;
-    const char ** filename_begin;
-    const char ** filename_end;
+    simple_queue_t queue;
 } global_state;
+//if initialization is success, return true
+bool init_global_state(struct SimpleThreadGlobal * t, size_t size){
+    pthread_mutex_init(&t->queueing_mutex,NULL);
+    t->thread_arr_size = size;
+    t->thread_arr = (pthread_t *)malloc(sizeof(*global_state.thread_arr) * global_state.thread_arr_size);
+    if (t->thread_arr == NULL){
+        return false;
+    }
+    return true;
+}
 
 typedef struct SimpleThreadReturn{
     int retval;
@@ -249,7 +304,6 @@ void destroy_thread_arg(worker_arg_t * arg){
     free(arg);
 }
 
-
 void * WorkerProc(void * args){
     worker_arg_t * arg = (worker_arg_t *)(args);
     worker_return_t * ret = create_worker_return();
@@ -258,123 +312,128 @@ void * WorkerProc(void * args){
     for(;;)
     {
         pthread_mutex_lock(&global_state.queueing_mutex);
-        if (global_state.method == From_CharArray){
-            if (__glibc_unlikely(global_state.filename_begin == global_state.filename_end)) {
-                pthread_mutex_unlock(&global_state.queueing_mutex);
-                break;
-            }
-            filename = *(global_state.filename_begin++);
-        }
-        else{
-            //unsafe.
-            int t = fscanf(stdin,"%s",filename_buf);
-            if (__glibc_unlikely(t != 1)) {
-                pthread_mutex_unlock(&global_state.queueing_mutex);
-                break;
-            }
-            filename = filename_buf;
-        }
+        filename = dequeue_from_simplecharqueue(&global_state.queue,filename_buf,FILENAME_BUF_SIZE);
         pthread_mutex_unlock(&global_state.queueing_mutex);
-
+        if(filename == NULL) break;
         ret->retval += SendOpAndReceiveFile(filename,&arg->addr);
         ret->op_count++;
     }
     destroy_thread_arg(arg);
     return ret;
 }
- 
-static bool stdinisatty;
-
-int main(int argc, const char *argv[]){
-    struct sockaddr_in addr;
-    const char * filename;
+//====
+// cmd parse
+//====
+static struct {
     const char * server_name;
-    in_port_t server_port = 0;
-    int arg_filename_start = 3;
-    int err;
-    int retval = 0;
+    in_port_t server_port;
+    bool stdinisatty;
+    int thread_number_option;
+} cmd_args = {
+    .server_name = "",
+    .server_port = 0
+};
 
-    init_bench_data();
-    stdinisatty = isatty(STDIN_FILENO);
+static const char * show_help_message(FILE * file,const char * argv0){
+    static const char * msg = 
+    "USAUE: %s SERVERNAME PORT [Option]... [FILENAME]...\n"
+    "Options and arguments: \n"
+    "-b or --benchmark\t:benchmark mode\n"
+    "-nv or --no-verbose\t:no progress bar\n"
+    "-h\t:print help message.\n";
+    fprintf(file,msg,argv0);
+    return msg;
+}
 
-    if (argc < (stdinisatty ? 4 : 3)){
-        fprintf(stderr,"USAUE: %s SERVERNAME PORT [Option]... [FILENAME]...\n",argv[0]);
+static int parse_arg(int argc,const char *argv[]){
+    int cur;
+    cmd_args.stdinisatty = isatty(STDIN_FILENO);
+    if (argc < (cmd_args.stdinisatty ? 4 : 3)){
+        show_help_message(stderr,argv[0]);
         return 1;
     }
-    server_name = argv[1];
-    server_port = atoi(argv[2]);
-    while(arg_filename_start < argc){
-        if (strcmp("-b",argv[arg_filename_start])==0
-        ||strcmp("--benchmark",argv[arg_filename_start])==0){
-            arg_filename_start++;
+    cmd_args.server_name = argv[1];
+    cmd_args.server_port = atoi(argv[2]);
+    if (cmd_args.server_port == 0){
+        fprintf(stderr,"port invalid\n");
+        return -1;
+    }
+    cmd_args.thread_number_option = 1;
+    for(cur = 3;cur < argc; cur++){
+        if (strcmp("-b",argv[cur])==0||strcmp("--benchmark",argv[cur])==0){
             bench.benchmode = true;
         }
-        else if(strcmp("-nv",argv[arg_filename_start]) == 0||strcmp("--no-verbose",argv[arg_filename_start])==0){
-            arg_filename_start++;
+        else if(strcmp("-nv",argv[cur]) == 0||strcmp("--no-verbose",argv[cur])==0){
             DisplayProgress = false;
         }
-        else if(strcmp("-t",argv[arg_filename_start]) == 0 || strcmp("--thread",argv[arg_filename_start]) == 0){
-            arg_filename_start++;
-            if (arg_filename_start >= argc){
+        else if(strcmp("-t",argv[cur]) == 0 || strcmp("--thread",argv[cur]) == 0){
+            cur++;
+            if (cur >= argc){
                 fprintf(stderr,"need number");
                 return -2;
             }
-            thread_number_option = atoi(argv[arg_filename_start++]);
-            if(thread_number_option == 0){
+            cmd_args.thread_number_option = atoi(argv[cur]);
+            if(cmd_args.thread_number_option == 0){
                 fprintf(stderr,"not number or zero");
                 return -2;
             }
         }
+        else if(strcmp("-h",argv[cur]) == 0 || strcmp("--help",argv[cur]) == 0){
+            show_help_message(stdout,argv[0]);
+            return 0;
+        }
         else break;
     }
-    if (server_port == 0){
-        fprintf(stderr,"port invalid\n");
-        return 1;
+    if (cmd_args.stdinisatty){
+        init_queue_from_chararray(&global_state.queue, &argv[cur],&argv[argc]);
     }
+    else{
+        init_queue_from_file(&global_state.queue,stdin);
+    }
+    
+    return 0;
+}
 
-    err = getsockaddrbyname(AF_INET,SOCK_STREAM,0,server_name,(struct sockaddr *)&addr);
+int main(int argc, const char *argv[]){
+    struct sockaddr_in addr;
+    const char * filename;
+    int err;
+    int retval = 0;
+
+    init_bench_data();
+    if(parse_arg(argc,argv) < 0) return EXIT_FAILURE;
+
+    err = getsockaddrbyname(AF_INET,SOCK_STREAM,0,cmd_args.server_name,(struct sockaddr *)&addr);
     if (err != 0){
         int check;
         fprintf(stderr,"netdb fail: %s\n",gai_strerror(err));
         //assume that sernmae is *.*.*.* and try to parse addr
-        check = inet_pton(AF_INET,server_name,&addr.sin_addr);
+        check = inet_pton(AF_INET,cmd_args.server_name,&addr.sin_addr);
         assert(check != -1);
         if (check == 0){
             fprintf(stderr,"parsing fail : invaild format\n");
-            return 1;
+            return -1;
         }
     }
     addr.sin_family = AF_INET;
-    addr.sin_port = htons(server_port);
+    addr.sin_port = htons(cmd_args.server_port);
 
     if (bench.benchmode){
         clock_gettime(bench.clock_id,&bench.begin);
     }
-    if(thread_number_option == 1){
+    if(cmd_args.thread_number_option == 1){
         char filename_buf[FILENAME_BUF_SIZE];
         for (;;){
-            if (stdinisatty){
-                if (arg_filename_start >= argc) break;
-                filename = argv[arg_filename_start++];
-            }
-            else{
-                //unsafe.
-                int t = fscanf(stdin,"%s",filename_buf);
-                if (t != 1) break;
-                filename = filename_buf;
-            }
+            filename = dequeue_from_simplecharqueue(&global_state.queue,filename_buf,FILENAME_BUF_SIZE);
+            if (filename == NULL) break;
+            
             retval += SendOpAndReceiveFile(filename,(struct sockaddr *)&addr);
             bench.op_count++;
         }
     }
     else{
         int i = 0;
-        global_state.method = stdinisatty ? From_CharArray : From_FileStream;
-        global_state.filename_begin = &argv[arg_filename_start];
-        global_state.filename_end = &argv[argc];
-        pthread_mutex_init(&global_state.queueing_mutex,NULL);
-        global_state.thread_arr_size = thread_number_option;
-        global_state.thread_arr = (pthread_t *)malloc(sizeof(*global_state.thread_arr) * global_state.thread_arr_size);
+        init_global_state(&global_state,cmd_args.thread_number_option);
         for (i = 0; i < global_state.thread_arr_size; i++){
             worker_arg_t * arg = create_thread_arg((struct sockaddr *)&addr);
             pthread_create(&global_state.thread_arr[i],NULL,WorkerProc,arg);