脚本执行时间[编辑]

Question

I read a serial port and send data to python, I want this chain to work for 10 seconds. The code below does not work:

sudo cat -v /dev/pts/2 | python3 bash_test.py 
pid=$!
sleep 10
kill -9 $pid

[UPDATE] eg bash_test.py

import sys
for line in sys.stdin:
    print(line,'\n')

Answer 1

You can use timeout :

sudo bash -c "cat -v /dev/pts/2 | timeout 10 python3 bash_test.py"

Command info:

NAME
       timeout - run a command with a time limit

SYNOPSIS
       timeout [OPTION] DURATION COMMAND [ARG]...
       timeout [OPTION]

Simple example for timeout :

timeout 3 sleep 10

The command here is sleep 10 but timeout will kill it after 3 seconds.

Answer 2

Try adding & sign after your sudo

sudo cat -v /dev/pts/2 | python3 bash_test.py &
pid=$!
sleep 10
kill -9 $pid

Answer 3

The following code open a "sub-bash" environment where the actual command is running. In this way it can run in background. There could be some problem if you are using threads or multiprocessing in the python script.

(sudo cat -v /dev/pts/2 | python3 bash_test.py) &
pid=$!
sleep 10
kill -9 $pid