diff --git a/.vscode/settings.json b/.vscode/settings.json
index aa9a253..b43fea8 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -5,6 +5,7 @@
     "files.associations": {
         "socket_wrapper.h": "c",
         "stdalign.h": "c",
-        "timerhelper.h": "c"
+        "timerhelper.h": "c",
+        "termio.h": "c"
     }
 }
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 5a0fe7d..fe4e98f 100644
--- a/Makefile
+++ b/Makefile
@@ -9,11 +9,13 @@ all:
 
 socket_wrapper.o: socket_wrapper.c socket_wrapper.h
 	$(CC) -c socket_wrapper.c -o socket_wrapper.o $(CFLAGS)
+display_bar.o: display_bar.c display_bar.h
+	$(CC) -c display_bar.c -o display_bar.o $(CFLAGS)
 
 client: socket_wrapper.o client.c
 	$(CC) -o client client.c socket_wrapper.o $(CFLAGS)
-server:  socket_wrapper.o server.c
-	$(CC) -o server server.c socket_wrapper.o $(CFLAGS)
+server:  socket_wrapper.o server.c display_bar.o
+	$(CC) -o server server.c socket_wrapper.o display_bar.o $(CFLAGS)
 p-server: socket_wrapper.o p-server.c
 	$(CC) -o p-server p-server.c socket_wrapper.o $(CFLAGS)
 p-client: socket_wrapper.o p-client.c
diff --git a/client.c b/client.c
index 69e8307..993c0f0 100644
--- a/client.c
+++ b/client.c
@@ -238,7 +238,7 @@ static bool init_queue_from_chararray(simple_queue_t * restrict q,const char **
 // 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->method = From_FileStream;
     q->fs = f;
     return true;
 }
diff --git a/display_bar.c b/display_bar.c
new file mode 100644
index 0000000..42c7de7
--- /dev/null
+++ b/display_bar.c
@@ -0,0 +1,115 @@
+#include<stdio.h>
+#include<stdbool.h>
+#include<stdarg.h>
+#include<string.h>
+#include<errno.h>
+#include<unistd.h>
+#include<termio.h>
+#include<pthread.h>
+
+#include "display_bar.h"
+#include "timerhelper.h"
+
+enum{
+#ifndef DEFAULT_PROGRESS_BAR_WIDTH
+    PROGRESS_BAR_WIDTH = 30,
+#else
+    PROGRESS_BAR_WIDTH = DEFAULT_PROGRESS_BAR_WIDTH;
+#endif
+#ifndef DEFAULT_MAX_TERMINAL_ROW
+    MAX_TERMINAL_ROW = 1000,
+#else
+    MAX_TERMINAL_ROW = MAX_TERMINAL_ROW;
+#endif
+};
+
+static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+static raw_progress_bar_t scrolled = 1;
+
+void ready_progress_bar(){
+    fflush(stdout);
+}
+
+void lock_scrolled(){
+    pthread_mutex_lock(&mutex);
+}
+void unlock_scrolled(){
+    pthread_mutex_unlock(&mutex);
+}
+
+void add_scrolled_unlocked(unsigned int i){
+    scrolled += i;
+}
+raw_progress_bar_t create_raw_progress_bar(){
+    int ret;
+    lock_scrolled();
+    ret = scrolled;
+    //make space for progress bar
+    fprintf(stdout,"\n");
+    scrolled++;
+    unlock_scrolled();
+    return ret;
+}
+
+void RawDisplayProgressBar(raw_progress_bar_t bar,size_t offset,size_t total,const char * filename){
+    char buf[PROGRESS_BAR_WIDTH];
+    size_t i;
+    double cur_progress = ((double)offset)/(double)total *100.f;
+    size_t cur_pos = (cur_progress / 100.0 * PROGRESS_BAR_WIDTH); //must be less than SIZE_MAX. other value is undefined behavior.
+    int pos;
+    struct winsize wnd_size;
+    if (offset == total)
+        cur_pos = PROGRESS_BAR_WIDTH;
+    for (i = 0; i < PROGRESS_BAR_WIDTH; i++){
+        if (i < cur_pos)
+            buf[i] = '=';
+        else if(i == cur_pos)
+            buf[i] = '>';
+        else buf[i] = '.';
+    }
+    lock_scrolled();
+    //if ioctl failed? what should i do...
+    ioctl(STDIN_FILENO,TIOCGWINSZ,(char *)&wnd_size);
+    if (wnd_size.ws_row < pos) return;
+    if (pos > MAX_TERMINAL_ROW) return;//optimization.
+    pos = scrolled - bar;
+    fprintf(stdout,"\x1b[%dA[%s]: %.2f%% %s bytes: %ld/%ld %d \x1b[%dB\r",pos,buf,cur_progress,filename,total,offset,pos,pos);
+    fflush(stdout);
+    unlock_scrolled();
+}
+bool isatty_file(FILE * file){
+    return isatty(fileno(file));
+}
+void myd_perror(const char * msg){
+    char buf[1024];
+    int err = errno;
+    strerror_r(errno,buf,sizeof(buf));
+    errno = err;
+    if (isatty(STDERR_FILENO)){
+        lock_scrolled();
+        scrolled++;
+        fprintf(stderr,"%s: %s\n",msg,buf);
+        unlock_scrolled();
+    }
+}
+
+void init_progress_bar(progress_bar_t * bar,int update_rate){
+    memset(bar,0,sizeof(*bar));
+    bar->bar = create_raw_progress_bar();
+    bar->update_rate = update_rate;
+}
+
+void DisplayProgressBar(progress_bar_t * bar,size_t offset,size_t total,const char * filename, bool sync){
+    unsigned diff;
+    struct timespec ts,dif;
+    clock_gettime(CLOCK_REALTIME,&ts);
+    if (!sync){
+        dif = timespec_sub(ts,bar->last_update);
+        diff = dif.tv_nsec / 1000000 + dif.tv_sec;
+        if (diff < bar->update_rate){
+            return;
+        }
+    }
+    bar->last_update = ts;
+    RawDisplayProgressBar(bar->bar,offset,total,filename);
+}
\ No newline at end of file
diff --git a/display_bar.h b/display_bar.h
new file mode 100644
index 0000000..b83fea6
--- /dev/null
+++ b/display_bar.h
@@ -0,0 +1,37 @@
+#include<stdio.h>
+#include<time.h>
+#include<stdbool.h>
+
+#ifndef _DISPLAY_BAR_H_
+#define _DISPLAY_BAR_H_
+
+typedef unsigned raw_progress_bar_t;
+
+void lock_scrolled();
+
+void unlock_scrolled();
+
+void ready_progress_bar();
+
+void add_scrolled_unlocked(unsigned int i);
+
+raw_progress_bar_t create_raw_progress_bar();
+
+void RawDisplayProgressBar(raw_progress_bar_t bar,size_t offset,size_t total,const char * filename);
+
+bool isatty_file(FILE * file);
+
+void myd_perror(const char * msg);
+
+typedef struct {
+    raw_progress_bar_t bar;
+    //millisecond unit
+    int update_rate;
+    struct timespec last_update;
+} progress_bar_t;
+
+void init_progress_bar(progress_bar_t * bar,int update_rate);
+
+void DisplayProgressBar(progress_bar_t * bar,size_t offset,size_t total,const char * filename, bool sync);
+
+#endif
\ No newline at end of file
diff --git a/server.c b/server.c
index 1ec080e..2f89ec8 100644
--- a/server.c
+++ b/server.c
@@ -17,6 +17,7 @@
 #include "socket_wrapper.h"
 #include "simple_circular_buffer.h"
 #include "timerhelper.h"
+#include "display_bar.h"
 
 #ifndef DEFAULT_MAX_LISTEN_SOCKET
 static const int MAX_LISTEN_SOCKET = 16;
@@ -61,7 +62,7 @@ enum{
 #endif
 };
 #define USE_TRACE
-#define USE_NO_QUEUE
+
 
 /*========
  *Operation
@@ -80,11 +81,11 @@ int send_fail(int sock,const char * msg){
     res.error_msg_size = strlen(msg);
     //os will be combining if tcp_autocorking emabled.
     if(send(sock,&res,sizeof(res),0) < 0){
-        perror("error msg send");
+        myd_perror("error msg send");
         return -1;
     }
     if (send(sock,msg,res.error_msg_size,0) < 0){
-        perror("error msg send");
+        myd_perror("error msg send");
         return -1;
     }
     return 0;
@@ -100,7 +101,7 @@ int send_errno(int sock){
     r.file_size = 0;
     r.error_msg_size = 0;
     if(send(sock,&r,sizeof(r),0)){
-        perror("errno send");
+        myd_perror("errno send");
         return -1;
     }
     return 0;
@@ -115,7 +116,7 @@ int read_request(int sock,uint8_t * buf,size_t bufsize){
     ssize_t n = recv_until_byte(sock,&p,sizeof(p),TIMEOUT);
     if (n < 0){
         if (n == -2) fprintf(stderr,"timeout!");
-        else perror("receive fail"); 
+        else myd_perror("receive fail"); 
         return -1;
     }
     if(bufsize <= ((size_t)p.file_url_size) + sizeof(p) + 1){
@@ -132,7 +133,13 @@ int read_request(int sock,uint8_t * buf,size_t bufsize){
     }
     n = recv_until_byte(sock,buf,p.file_url_size,TIMEOUT);
     buf[p.file_url_size] = '\0';    //truncate
-    fprintf(stdout,"str size: %d, request %s\n",p.file_url_size,buf);
+    if (isatty_file(stdout)){
+        lock_scrolled();
+        add_scrolled_unlocked(1);
+        fprintf(stdout,"str size: %d, request %s\n",p.file_url_size,buf);
+        unlock_scrolled();
+    }
+    else fprintf(stdout,"str size: %d, request %s\n",p.file_url_size,buf);
     if(strchr((char *)buf,'/') != NULL){
         send_fail(sock,"Illegal character /");
         return -1;
@@ -154,6 +161,7 @@ int send_response(int sock,int fd, uint8_t * buf, size_t bufsize){
     struct stat st;
     off_t offset = 0;
     ssize_t readed = 0;
+    progress_bar_t pbar;
     r.res = RES_OK;
     r.err_number = 0;
     r.error_msg_size = 0;
@@ -165,33 +173,37 @@ int send_response(int sock,int fd, uint8_t * buf, size_t bufsize){
     }
     r.file_size = st.st_size;
     if(send(sock,&r,sizeof(r),0)<0){
-        perror("send fail");
+        myd_perror("send fail");
         return -1;
     }
+    init_progress_bar(&pbar,10);
 #ifdef USE_SENDFILE
     while (r.file_size != offset)
     {
         size_t count = SEND_FILE_CHUNK_SIZE < (r.file_size - offset) ? SEND_FILE_CHUNK_SIZE : (r.file_size - offset);
         if((readed = sendfile(sock,fd,&offset,count)) < 0){
-            perror("send file fail");
+            myd_perror("send file fail");
             return -1;
         }
+        DisplayProgressBar(&pbar,offset,r.file_size,"",false);
     }
 #else
     while (offset < r.file_size)
     {
         readed = bufsize < (r.file_size - offset) ? bufsize : r.file_size - offset;
         if(read(fd,buf,readed)<0){
-            perror("send response read fail");
+            myd_perror("send response read fail");
             return -1;
         }
         if(send(sock,buf,readed,0)<0){
-            perror("send response send fail");
+            myd_perror("send response send fail");
             return -1;
         }
         offset += readed;
+        usleep(500000);
+        DisplayProgressBar(&pbar,offset,r.file_size,"",false);
     }
-    
+    DisplayProgressBar(&pbar,offset,r.file_size,"",true);
 #endif
     return 0;
 }
@@ -308,7 +320,6 @@ void * worker_proc(void * data){
     struct timespec ts,ts_middle,ts_end;
     #endif
     for(;;){
-
         pthread_mutex_lock(&globalState.sock_mutex);
         while (queue_isempty(&globalState.socks)){
             pthread_cond_wait(&globalState.ready,&globalState.sock_mutex);
@@ -329,10 +340,15 @@ void * worker_proc(void * data){
         clock_gettime(Trace_Timer_ID,&ts_end);
         struct timespec tophalf = timespec_sub(ts_middle,ts);
         struct timespec bottomhelf = timespec_sub(ts_end,ts_middle);
-        fprintf(stderr,"top : %ld ns, bottom : %ld ns\n",tophalf.tv_nsec,bottomhelf.tv_nsec);
+        if(isatty_file(stderr)){
+            lock_scrolled();
+            add_scrolled_unlocked(1);
+            fprintf(stderr,"top : %ld ns, bottom : %ld ns\n",tophalf.tv_nsec,bottomhelf.tv_nsec);
+            unlock_scrolled();
+        }
     #endif
         if(close(csock) < 0)
-            perror("csock close error");
+            myd_perror("csock close error");
     }
     destory_worker_argument(args);
     return NULL;
@@ -356,10 +372,16 @@ void * worker_proc(void * data){
     clock_gettime(Trace_Timer_ID,&ts_end);
     struct timespec tophalf = timespec_sub(ts_middle,ts);
     struct timespec bottomhelf = timespec_sub(ts_end,ts_middle);
-    fprintf(stderr,"top : %ld ns, bottom : %ld ns\n",tophalf.tv_nsec,bottomhelf.tv_nsec);
+    if(isatty_file(stderr)){
+        lock_scrolled();
+        add_scrolled_unlocked(1);
+        fprintf(stderr,"top : %ld ns, bottom : %ld ns\n",tophalf.tv_nsec,bottomhelf.tv_nsec);
+        unlock_scrolled();
+    }
+    else fprintf(stderr,"top : %ld ns, bottom : %ld ns\n",tophalf.tv_nsec,bottomhelf.tv_nsec);
     #endif
     if(close(csock) < 0)
-        perror("csock close error");
+        myd_perror("csock close error");
     destory_worker_argument(args);
     return NULL;
 }
@@ -382,17 +404,17 @@ int main(int argc, const char *argv[]){
         int d = parse_args(argc,argv,&binding_port_number);
         if(d != 0 ) return d;
     }
-    
+    ready_progress_bar();
     sock = socket(AF_INET,SOCK_STREAM,0);
     atexit(safe_exit);
     if(sock < 0){
-        perror("sock create fail");
+        myd_perror("sock create fail");
         return 1;
     }
     else {
         int option = 1;
         if(setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&option,sizeof(option)) < 0){
-            perror("setsockopt");
+            myd_perror("setsockopt");
         }
     }
     bufsize = getBufferSizeFrom(sock);
@@ -412,17 +434,23 @@ int main(int argc, const char *argv[]){
     addr.sin_port = htons(binding_port_number);
 
     if(bind(sock, (struct sockaddr *)&addr,sizeof(addr)) < 0){
-        perror("bind failed");
+        myd_perror("bind failed");
         return 1;
     } else {
         char ip_buf[INET_ADDRSTRLEN];
         const char * msg = inet_ntop(AF_INET,&addr.sin_addr,ip_buf,sizeof(ip_buf));
         assert(msg != NULL);
-        fprintf(stdout,"server bind on %s:%d\n",msg ,binding_port_number);
+        if(isatty_file(stdout)){
+            lock_scrolled();
+            add_scrolled_unlocked(1);
+            fprintf(stdout,"server bind on %s:%d\n",msg ,binding_port_number);
+            unlock_scrolled();
+        }
+        else fprintf(stdout,"server bind on %s:%d\n",msg ,binding_port_number);
     }
 
     if(listen(sock,MAX_LISTEN_SOCKET) < 0){
-        perror("listen failed");
+        myd_perror("listen failed");
         return 1;
     }
 
@@ -430,7 +458,13 @@ int main(int argc, const char *argv[]){
     {
         char ip_buf[INET_ADDRSTRLEN];
         const char * msg = inet_ntop(AF_INET,&client_addr.sin_addr,ip_buf,sizeof(ip_buf));
-        fprintf(stdout,"Connected on : %s:%d\n",msg == NULL ? "(null)" : msg , ntohs(addr.sin_port));
+        if(isatty_file(stdout)){
+            lock_scrolled();
+            add_scrolled_unlocked(1);
+            fprintf(stdout,"Connected on : %s:%d\n",msg == NULL ? "(null)" : msg , ntohs(addr.sin_port));
+            unlock_scrolled();
+        }
+        else fprintf(stdout,"Connected on : %s:%d\n",msg == NULL ? "(null)" : msg , ntohs(addr.sin_port));
 #ifdef USE_TRACE
         struct timespec ts;
         clock_gettime(Trace_Timer_ID, &ts);