CODEWITHSUNDEEP
pythonsubprocessstdout
hypersonics
hypersonics

Reputation: 1134

Writing the stdout of subprocess to a file using communicate

I am using subprocess to run a executable and piping the output of it using communicate. Finally, I write the contents of communicate to a file. The exact code is shown below

run = subprocess.Popen(['executable'], stdout=subprocess.PIPE)
output = run.communicate()[0]
logfile = open('run.log', 'a')
logfile.write(output)
logfile.close()

In the above process, the logfile is written at the end of the run. However, is there a way to write the output to the log as the executable is running?

Upvotes: 0

Views: 2041

Answers (2)

hypersonics
hypersonics

Reputation: 1134

I think I found the solution to this:

logfile = ('run.log', 'w')
run = subprocess.Popen(['executable'], stdout = logfile)
run.wait()
logfile.close()

The first line creates the run.log for writing and stdout writes directly to the logfile as the executable is running. The run.wait() waits for the executable to complete and then the log file is closed.

Upvotes: 0

Padraic Cunningham
Padraic Cunningham

Reputation: 180471

You mean something like:

with open("run.log","a") as f:
      run = subprocess.Popen(['executable'], stdout=f)

Upvotes: 2

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