I want to execute this command from a python script:
iw wlan0 scan | sed -e 's#(on wlan# (on wlan#g' | awk -f > scan.txt
I tried like the following
from subprocess import call
call(["iw wlan0 scan | sed -e 's#(on wlan# (on wlan#g' | awk -f > scan.txt"])
but I get an error
SyntaxError: EOL while scanning string literal
How can I do that?
Pass shell=True to subprocess.call:
call("iw wlan0 scan | sed -e 's#(on wlan# (on wlan#g' | awk -f scan.txt", shell=True)
Note that shell=True is not a safe option always.
shell=True runs the command as if you would have entered it into your OS' terminal. That means as long as it's a fixed string which you verified, it's pretty safe. But never use shell=True if part of the command is not constant but from an insecure source (e.g. user input). Imagine this: text = input(); call("echo " + text, shell=True) and the user inputs I hate you; rm -rf /While setting shell=True and removing the list brackets around the string will solve the immediate problem, running sed and Awk from Python is just crazy.
import subprocess
iw = subprocess.check_output(['is', 'wlan0', 'scan']) # shell=False
with open('scan.txt', 'r') as w:
for line in iw.split('\n'):
line = line.replace('(on wlan', ' (on wlan')
# ... and whatever your Awk script does
w.write(line + '\n')
The commands module is simpler to use:
import commands
output = commands.getoutput("iw wlan0 scan | sed -e 's#(on wlan# (on wlan#g' | awk -f scan.txt")
import osand then:os.system("iw wlan0 scan | sed -e 's#(on wlan# (on wlan#g' | awk -f scan.txt")mawk -fis an error. Presumably you have a script file you want to run.