Blink for every ssh sessions.

README.md

Blink for SSH User

🔴 Blink in proportion to the number of active ssh sessions! ⚪

Demo?

Why?

Because plain blink sample is super boring. And also this kind of useful!

sshblink.py

#!/usr/bin/env python
from subprocess import Popen, PIPE
from shlex import split
import OPi.GPIO as GPIO
from time import sleep

pin = 7

def number_of_active_ssh():
    p1 = Popen(split("ps ax"), stdout=PIPE)
    p2 = Popen(split("grep sshd"), stdin=p1.stdout, stdout=PIPE)
    p2 = Popen(split("grep -v grep"), stdin=p2.stdout, stdout=PIPE)
    lines = p2.stdout.readlines()
    if len(lines) < 2:
        return 0
    else:
        return len(lines)-1

# Setting up GPIO
GPIO.setboard(GPIO.ZERO)
GPIO.setmode(GPIO.BOARD)
GPIO.setup(pin, GPIO.OUT)

# Main loop
try:
    print ("Press CTRL+C to exit")
    while True:
        active_sessions = number_of_active_ssh()
        
        if active_sessions == 0:
            GPIO.output(pin, 0)
            sleep(1)
            # print("No Active Session")
        else:
            # print("There are total of {} active session(s).".format(active_sessions))
            blink_rate = 1/(2.0*active_sessions)
            for i in range(active_sessions):
                GPIO.output(pin, 1)
                sleep(blink_rate)
                GPIO.output(pin, 0)
                sleep(blink_rate)

except KeyboardInterrupt:
    GPIO.output(pin, 0)
    GPIO.cleanup()