I would like to run a process with subprocess.Popen() and communicate with it through the python shell, like the subprocess.Popen usual behavior. Beside that, I would like to discursively log the STDIN and STDOUT to a logfile.
How can I do it?
- What do you mean by discursively ? Do you mean they both log to the same file ?Appleman1234– Appleman12342012-02-14 20:44:00 +00:00Commented Feb 14, 2012 at 20:44
- yes, but not just append the STDOUT after the STDIN. I need it discursively so I can tell which input brought any output.iTayb– iTayb2012-02-14 20:46:56 +00:00Commented Feb 14, 2012 at 20:46
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1 Answer
Assuming discursively means rambling and rambling means all in the same file, then the following snippet is what you requested.
Discursive logging with discrimination of the source and interaction
Override its communicate method like similar question here
import subprocess def logcommunicate(self, s): self.logfilehandle.write("Input "+s) std = self.oldcommunicate(s) self.logfilehandle.write("Output "+std[0]) return std subprocess.Popen.oldcommunicate = subprocess.Popen.communicate subprocess.Popen.communicate = logcommunicate logfh = open("/tmp/communicate.log", "a") proc = subprocess.Popen(['cat'], stdin=subprocess.PIPE, stdout=subprocess.PIPE) proc.logfilehandle = logfh result = proc.communicate("hello there\n") print result Discursive logging with discrimination of the source
First use StringIO instead of files, then subclass StringIO to override its write method to open that appends timestamp and source. Then write a custom compare function that sorts based on timestamp and source, timestamp first and then source Input and then output
with open("file.log","wb") as in logfile: out = MyOutPutStringIO.StringIO() in = MyInputStringIO.StringIO() subprocess.Popen(cmd, shell=True, universal_newlines = True, stdin=in, stdout=out) #Then after you are done linestotal = [] for line in in.readlines(): linestotal.append(line) for line in out.readlines(): linestotal.append(line) linestotal.sort(customsortbasedontimestampandinput) for line in linestotal.readlines(): logwrite.write(line) Discursive logging
with open("file.log","wb") as in logfile: subprocess.Popen(cmd, shell=True, universal_newlines = True, stdin=logfile, stdout=logfile) The opposite is shown below
Cursive logging
with open("stdout.txt","wb") as out: with open("stderr.txt","wb") as err: with open("stdin.txt","wb") as in: subprocess.Popen(cmd, shell=True, universal_newlines = True, stdin=in,stdout=out,stderr=err) 
2 Comments
iTayb
Maybe I wasn't clear enough - I would like to communicate with the process through the python shell, like the subprocess.Popen usual behavior. Beside that, I would like to log the STDIN and STDOUT to a logfile.
iTayb
The input comes from a file in your example... I want to control the process with the standard input interface. I also want the output to show on the python shell. The only difference is that I want to log all this input/output traffic.