I need to run a subprocess to do traceroute.
I'd like to filter traceroute output, when it output the first ASN (something like AS11223344). Write this ASN and IP to a specific file. 
How to find AS\d+ in a subprocess output?? Then save to a file.
Then terminate the subprocess.
The output is a lot of things like this : 
222.221.28.57  20.37 ms  AS4134
