[cc-ing back to the list; please keep the conversation over there...]
On 23/05/2011 13:11, vijay swaminathan wrote:
What I want to achieve is, I want to run a batch file on a command prompt.
The reason for using thread is not for running multiple scripts
simultaneously. It is just to monitor my script running in command
prompt. only on closing the command prompt, I like to perform some more
actions. so I look to monitor my thread. Hope it is clear until now.
Ok. That's perfectly clear.
the below mentioned code does not invoke the command prompt at all. Does
the subprocess.call take care of invoking the command prompt?
Adding shell=True invokes %COMSPEC% (usually cmd.exe) under the covers.
How do you know it's not invoking the command prompt? Does your
batch file generate output? And is that output generated? Without
the CREATE_NEW_CONSOLE flag, you won't see an extra box pop up, but
unless you specifically want one, then don't bother.
OK, baby steps. Here's a batch file:
<tjg.bat>
@echo Hello
</tjg.bat>
and here's a Python script which runs it:
<tjg.py>
import subprocess
subprocess.call ("tjg.bat", shell=True)
</tjg.py>
I opened a console (cmd.exe), ran tjg.py and, as expected, "Hello"
appears in the same console. Note that, if I hadn't made the .bat
file generate some output I wouldn't have seen anything but it
would still have worked.
I now make the .bat file do something more long-winded, such as
fire up a Python session which waits for five seconds and then
completes:
<tjg.bat>
@echo off
echo Starting
python -c "import time; time.sleep (5)"
echo Finished
</tjg.bat>
When I run tjg.py again, I see "Starting" and then a pause of
5 seconds, and then "Finished".
Now let's make the Python program monitor to see when that batch has
finished by watching the isAlive status and then sleeping for a second:
<tjg.py>
import subprocess
import threading
import time
def run_tjg ():
subprocess.call ("tjg.bat", shell=True)
t = threading.Thread (target=run_tjg)
t.start ()
while t.isAlive ():
print "is alive"
time.sleep (1)
print "Thread is complete"
</tjg.py>
When I run this, I get a mixture of output, depending on what
gets to the console first, but essentially I see the batch file
starting, I get a series of about 5 "is alive" messages, then
the batch file "Finished" message and the Python "Thread is
complete" message.
Does that work for you?
TJG
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