Question

I am executing the python command,

proc = subprocess.Popen(cmd,
                        shell=False,
                        stdin=subprocess.PIPE,
                        stdout=subprocess.PIPE,
                        stderr=subprocess.PIPE,
                        )

after executing command i want to read the stderr and stdout

res = proc.stderr.read()

in res i am expecting any error or ‘ ‘

but the reading the stderr is taking infinite time is get hang not reading the values what ever the result it.it goes in infinite time.

Some time back same code is working fine but not idea why its not reading stderr now.

Any Hint, thanks.

Answer 1

Instead of explicitly calling stderr.read(), just do a communicate on the proc.

output, error = proc.communicate()

That way you would get the output and error by communicating with the process.