Any way to assign terminal output to variable with python?
Solution 1
os.system
returns a return value indicating the success or failure of the command. It does not return the output from stdout or stderr. To grab the output from stdout (or stderr), use subprocess.Popen
.
import subprocess
proc=subprocess.Popen('echo "to stdout"', shell=True, stdout=subprocess.PIPE, )
output=proc.communicate()[0]
print output
See the wonderfully written Python Module of the Week blog.
Solution 2
os.system returns the exit code of the executed command, not its output. To do this you would need to use either commands.getoutput (deprecated) or subprocess.Popen:
from subprocess import Popen, PIPE
stdout = Popen('your command here', shell=True, stdout=PIPE).stdout
output = stdout.read()
Solution 3
Much simplest way
import commands
cmd = "ls -l"
output = commands.getoutput(cmd)
Solution 4
You probably want subprocess.Popen.
Comments
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Gordon Fontenot over 3 years
I need to grab the duration of a video file via python as part of a larger script. I know I can use ffmpeg to grab the duration, but I need to be able to save that output as a variable back in python. I thought this would work, but it's giving me a value of 0:
cmd = 'ffmpeg -i %s 2>&1 | grep "Duration" | cut -d \' \' -f 4 | sed s/,//' % ("Video.mov") duration = os.system(cmd) print duration
Am I doing the output redirect wrong? Or is there simply no way to pipe the terminal output back into python?