diff --git a/docs/file.rst b/docs/file.rst
index 06cc547..79e7652 100644
--- a/docs/file.rst
+++ b/docs/file.rst
@@ -83,7 +83,7 @@ File
 
 .. py:function:: pydu.file.touch(path):
 
-    open a file as write,and then close it.
+    Open a file as write,and then close it.
 
     >>> from pydu.file import touch
     >>> touch('test.txt')
@@ -105,8 +105,3 @@ File
 
     >>> from pydu.file import link
     >>> link('test.txt','test.link')
-
-
-
-
-
diff --git a/pydu/cmd.py b/pydu/cmd.py
index 195ab46..e01f5db 100644
--- a/pydu/cmd.py
+++ b/pydu/cmd.py
@@ -11,16 +11,14 @@ def run(cmd, wait=True, shell=True, timeout=0, timeinterval=1):
     if not wait:
         return p
 
-    if not timeout:
-        stdout, _ = p.communicate()
-        return p.poll(), stdout
+    if timeout:
+        while timeout > 0 and p.poll() is None:
+            timeout = timeout - timeinterval
+            time.sleep(timeinterval)
+        if p.poll() is None:
+            p.kill()
+            return p.poll(), 'Run timeout'
 
-    while timeout > 0 and p.poll() is None:
-        timeout = timeout - timeinterval
-        time.sleep(timeinterval)
-    if p.poll() is None:
-        p.kill()
-        return p.poll(), 'Run timeout'
     stdout, _ = p.communicate()
     return p.poll(), stdout
 
diff --git a/pydu/network.py b/pydu/network.py
index 8eb70bd..b9efb56 100644
--- a/pydu/network.py
+++ b/pydu/network.py
@@ -41,6 +41,6 @@ def _is_ip(ip, af):
 def get_free_port():
     s = socket.socket(socket.AF_INET, type=socket.SOCK_STREAM)
     s.bind(('127.0.0.1', 0))
-    address, port = s.getsockname()
+    _, port = s.getsockname()
     s.close()
     return port