diff --git a/README.md b/README.md
index 65b2581..860c8d9 100644
--- a/README.md
+++ b/README.md
@@ -91,11 +91,7 @@ If you think `-O3` isn't that safe and stable, you could choose:
 
 ![usage](./doc/gif/help.gif)
 
-If your system is `Windows` and you want to output unicode,please use this command before running nasal:
-
-> chcp 65001
-
-or you could write this in nasal code:
+If your system is `Windows` and you want to output unicode, you could write this in nasal code:
 
 ```javascript
 if(os.platform()=="windows")
diff --git a/doc/README_zh.md b/doc/README_zh.md
index 570c846..86fc322 100644
--- a/doc/README_zh.md
+++ b/doc/README_zh.md
@@ -80,11 +80,7 @@ __注意__: 如果你想直接下载发行版提供的zip/tar.gz压缩包来构
 
 ![usage](../doc/gif/help.gif)
 
-如果你的操作系统是 `Windows` 且想输出unicode，请保证控制台代码页支持utf-8，使用下面这个命令启用代码页:
-
-> chcp 65001
-
-或者直接在nasal代码里写这个来开启:
+如果你是 `Windows` 用户且想正常输出unicode，在nasal代码里写这个来开启unicode代码页:
 
 ```javascript
 if(os.platform()=="windows")
diff --git a/nasal_gc.h b/nasal_gc.h
index 21f1d7a..52e05c5 100644
--- a/nasal_gc.h
+++ b/nasal_gc.h
@@ -276,8 +276,7 @@ std::ostream& operator<<(std::ostream& out,nas_vec& vec)
         return out;
     }
     vec.printed=true;
-    usize iter=0;
-    usize size=vec.elems.size();
+    usize iter=0,size=vec.elems.size();
     out<<'[';
     for(auto& i:vec.elems)
         out<<i<<",]"[(++iter)==size];
@@ -331,8 +330,7 @@ std::ostream& operator<<(std::ostream& out,nas_hash& hash)
         return out;
     }
     hash.printed=true;
-    usize iter=0;
-    usize size=hash.elems.size();
+    usize iter=0,size=hash.elems.size();
     out<<'{';
     for(auto& i:hash.elems)
         out<<i.first<<':'<<i.second<<",}"[(++iter)==size];
diff --git a/stl/process_bar.nas b/stl/process_bar.nas
index 1575931..1a846dc 100644
--- a/stl/process_bar.nas
+++ b/stl/process_bar.nas
@@ -4,8 +4,10 @@
 
 var process_bar={
     bar:nil,
+    high_resolution_bar:nil,
     spinner:nil
 };
+
 process_bar.bar=func(){
     var bar={
         solid_triangle_right:"▶",
@@ -62,6 +64,45 @@ process_bar.bar=func(){
         };
     };
 }();
+
+# return a high resolution progress bar
+# example:
+# var bar=process_bar.high_resolution_bar(40);
+# for(var i=0;i<=1;i+=0.001){
+#     print(bar.bar(i,40),'\r');
+#     unix.sleep(0.001);
+# }
+# println();
+process_bar.high_resolution_bar=func(){
+    var block=["▏","▎","▍","▌","▋","▊","▉","█"];
+    return func(length){
+        return {
+            bar: func(number){
+                if(number>1)
+                    number=1;
+                if(number<0)
+                    number=0;
+                var block_len=number*length;
+                var complete_block=int(block_len);
+                var decimal=block_len-complete_block;
+                var progress=complete_block+(decimal!=0);
+                var s="|";
+                for(var i=0;i<complete_block;i+=1){
+                    s~="█";
+                }
+                if(decimal!=0){
+                    s~=block[int(decimal*10)/10*size(block)];
+                }
+                for(var i=0;i<length-progress;i+=1){
+                    s~=" ";
+                }
+                s~="|";
+                return s;
+            }
+        };
+    };
+}();
+
 process_bar.spinner=func(){
     var generate_scrolling_spinner=func(s){
         if(typeof(s)!="str")
diff --git a/test/calc.nas b/test/calc.nas
index 061c488..74321ad 100644
--- a/test/calc.nas
+++ b/test/calc.nas
@@ -106,7 +106,7 @@ var count=func(s,c){
 }
 
 var column=func(number){
-    number=number>=1000?int(number/1000)~'k':str(number);
+    number=number>=1000?substr(str(number/1000),0,3)~'k':str(number);
     return rightpad(number,6);
 }
 
diff --git a/test/coroutine.nas b/test/coroutine.nas
index 0c4b07d..ccc0dcb 100644
--- a/test/coroutine.nas
+++ b/test/coroutine.nas
@@ -44,8 +44,10 @@ var total=1000; # ms
 var co=coroutine.create(productor);
 var tm=maketimestamp();
 
+if(os.platform()=="windows")
+    system("chcp 65001");
 var counter=0;
-var bar=process_bar.bar("block","point","line",40);
+var bar=process_bar.high_resolution_bar(40);
 var consumer=func(){
     counter+=1;
     for(var i=0;i<5;i+=1)
diff --git a/test/md5compare.nas b/test/md5compare.nas
index 33eaf37..54ce4c2 100644
--- a/test/md5compare.nas
+++ b/test/md5compare.nas
@@ -13,7 +13,7 @@ var compare=func(){
         var total=end-begin;
         var timestamp=maketimestamp();
         timestamp.stamp();
-        var bar=process_bar.bar(front:os.platform()=="windows"?"sharp":"block",back:"point",sep:"line",length:50);
+        var bar=process_bar.high_resolution_bar(50);
         for(var i=begin;i<end;i+=1){
             var s="";
             for(var j=0;j<i;j+=1){
@@ -76,7 +76,7 @@ var filechecksum=func(){
     var total=size(files);
     var timestamp=maketimestamp();
     timestamp.stamp();
-    var bar=process_bar.bar(front:os.platform()=="windows"?"sharp":"block",back:"point",sep:"line",length:50);
+    var bar=process_bar.high_resolution_bar(50);
     forindex(var i;files){
         var f=io.fin(files[i]);
         var res=md5(f);
@@ -94,5 +94,7 @@ var randomchecksum=func(){
         compare(i,i+512);
 }
 
+if(os.platform()=="windows")
+    system("chcp 65001");
 filechecksum();
 randomchecksum();
\ No newline at end of file
diff --git a/test/occupation.nas b/test/occupation.nas
index 6e609f9..e2fb228 100644
--- a/test/occupation.nas
+++ b/test/occupation.nas
@@ -47,7 +47,7 @@ func(){
         var mem_occ=(mem.MemTotal-mem.MemFree)/mem.MemTotal*100;
         var cpu_occ=cpu_occupation();
         var key=libkey.nonblock();
-        var bar=process_bar.bar("block","point","line",25);
+        var bar=process_bar.high_resolution_bar(25);
         if(key!=nil and chr(key)=="q")
             break;
         println("\e[1;1H\e[1m Memory total(GB)    : \e[0m\e[36m",mem.MemTotal/1024/1024,"\e[0m");
diff --git a/test/ppmgen.nas b/test/ppmgen.nas
index 69f2851..ded1017 100644
--- a/test/ppmgen.nas
+++ b/test/ppmgen.nas
@@ -15,7 +15,9 @@ var ppm=func(filename,width,height,RGB){
 
 var width=1280;
 var height=720;
-var bar=process_bar.bar(front:os.platform()=="windows"?"sharp":"block",back:"point",sep:"line",length:50);
+var bar=(os.platform()=="windows")?
+    process_bar.bar(front:"sharp",back:"point",sep:"line",length:50):
+    process_bar.high_resolution_bar(50);
 var f=func(i,j){
     var (yMin,yMax,xMin,xMax)=(-1.35,1.35,-3.3,1.5);
     var (yDel,xDel)=(yMax-yMin,xMax-xMin);