I want to get output from os.system("nslookup google.com") but instead I always get 0, when printing it. Why is this, and how can I fix this? (Python 3, Mac)
(I looked at How to store the return value of os.system that it has printed to stdout in python? - But I didn't understand it ~ I'm new to python)
Use subprocess:
import subprocess
print(subprocess.check_output(['nslookup', 'google.com']))
If the return code is not zero it will raise a CalledProcessError exception:
try:
print(subprocess.check_output(['nslookup', 'google.com']))
except subprocess.CalledProcessError as err:
print(err)
os.system only returns the exit code of the command. Here 0 means success. Any other number stands for an operating-system-dependent error. The output goes to stdout of this process. subprocess intends to replace os.system.
subprocess.check_output is a convenience wrapper around subprocess.Popen that simplifies your use case.
subprocess not os.system.
FileNotFoundError: [Errno 2] No such file or directory: with subprocessshell=True as argument.
os.system("ls")only returns the exit_code forlswhich is a unix integer status from the operating system for the process. 0 here means "no-error". Both the stdout and stderr of os.system is piped into your python program's stdout and stderr. So either you re-implement this stdout redirection manually, or use a different python function that does this work automatically for you, one example of many beingsubprocess.