Beginner here, how to call a bash-script from python properly?

Shell Programming and Scripting
1

Hi everyone,
i have the following script.sh:

foo='lsusb | grep Webcam | cut -c16-18'
sudo /home/user/public/usbreset /dev/bus/usb/001/$foo

when i try to call this script from python using

subprocess.call("script.sh", shell=True)

it seems that only 'sudo /home/user/public/usbreset' is being executed. how can i fix this properly?
Thanks in advance!

2

How do you tell that only the quoted line is executed?

3

uhm sorry, i meant to say that usbreset without the parameter
/dev/bus/usb/001/$foo
is being executed.

4

Is the entire parameter missing or is just the $foo empty?

5

well, your question has given me the answer as i used set -x to enable echo now, and the command is being executed as

 
sudo /home/user/public/usbreset /dev/bus/usb/001/lsusb | grep Webcam | cut -c16-18

So maybe i can use | to combine both commands into one line?

6

You used apostrophes ' in lieu of backticks ` for the command substitution, so it failed and you had the literal string for the parameter.

---------- Post updated at 12:42 ---------- Previous update was at 12:40 ----------

And yes, you could use

sudo /home/user/public/usbreset /dev/bus/usb/001/$(lsusb | grep Webcam | cut -c16-18)

Backticks are deprecated and should be replaced by $( ... ) for command substitution.

7

thanks a lot!!!