try asyncio

async_cmd.py

@@ -0,0 +1,87 @@
+#!/usr/bin/python
+#
+# Runner with stdout/stderr catcher
+#
+from sys import argv
+from subprocess import Popen, PIPE
+import os, io
+from threading import Thread
+from queue import Queue,Empty
+
+def __main__():
+    if (len(argv) > 1) and (argv[-1] == "-sub-"):
+        import time, sys
+        print("Application runned!")
+        time.sleep(2)
+        print("Slept 2 second")
+        time.sleep(1)
+        print("Slept 1 additional second")
+        time.sleep(2)
+        sys.stderr.write("Stderr output after 5 seconds")
+        print("Eol on stdin")
+        sys.stderr.write("Eol on stderr\n")
+        time.sleep(1)
+        print("Wow, we have end of work!")
+    else:
+        os.environ["PYTHONUNBUFFERED"]="1"
+        try:
+            p = Popen( argv + ["-sub-"],
+                       bufsize=0, # line-buffered
+                       stdin=PIPE, stdout=PIPE, stderr=PIPE )
+        except WindowsError as W:
+            if W.winerror==193:
+                p = Popen( argv + ["-sub-"],
+                           shell=True, # Try to run via shell
+                           bufsize=0, # line-buffered
+                           stdin=PIPE, stdout=PIPE, stderr=PIPE )
+            else:
+                raise
+        inp = Queue()
+        sout = io.open(p.stdout.fileno(), 'rb', closefd=False)
+        serr = io.open(p.stderr.fileno(), 'rb', closefd=False)
+        def Pump(stream, category):
+            queue = Queue()
+            def rdr():
+                while True:
+                    buf = stream.read1(8192)
+                    if len(buf)>0:
+                        queue.put( buf )
+                    else:
+                        queue.put( None )
+                        return
+            def clct():
+                active = True
+                while active:
+                    r = queue.get()
+                    try:
+                        while True:
+                            r1 = queue.get(timeout=0.005)
+                            if r1 is None:
+                                active = False
+                                break
+                            else:
+                                r += r1
+                    except Empty:
+                        pass
+                    inp.put( (category, r) )
+            for tgt in [rdr, clct]:
+                th = Thread(target=tgt)
+                th.setDaemon(True)
+                th.start()
+        Pump(sout, 'stdout')
+        Pump(serr, 'stderr')
+
+        while p.poll() is None:
+            # App still working
+            try:
+                chan,line = inp.get(timeout = 1.0)
+                if chan=='stdout':
+                    print("STDOUT>>", line, "<?<")
+                elif chan=='stderr':
+                    print(" ERROR==", line, "=?=")
+            except Empty:
+                pass
+        print("Finish")
+
+if __name__ == '__main__':
+    __main__()

pipecmd.py

@@ -0,0 +1,35 @@
+import sys
+from subprocess import PIPE, Popen
+from threading  import Thread
+
+try:
+    from Queue import Queue, Empty
+except ImportError:
+    from queue import Queue, Empty  # python 3.x
+
+ON_POSIX = 'posix' in sys.builtin_module_names
+
+def enqueue_output(out, queue):
+    for line in iter(out.readline, b''):
+        queue.put(line)
+    out.close()
+
+p = Popen(['dir'], shell=True, stdout=PIPE, bufsize=1, close_fds=ON_POSIX)
+q = Queue()
+t = Thread(target=enqueue_output, args=(p.stdout, q))
+t.daemon = True # thread dies with the program
+t.start()
+
+# ... do other things here
+
+# read line without blocking
+wait = True
+while wait:
+    try:
+        line = q.get_nowait() # or q.get(timeout=.1)
+    except Empty:
+        print('no output yet')
+    else: # got line
+        # ... do something with line
+        print(line)
+        break