How do I start two different Python scripts with rc.local?

Question

I have two different Python scripts I'd like to run at start-up on my Raspberry Pi A+. Both work perfectly if I run them via sudo python filename.py. I can get the first one to run, but not the second one in the rc.local below. It doesn't matter if I switch them or not, only the first one runs, and only if I don't have & at the end.

Here is my /etc/rc.local:

(Notice the commented-out version - it doesn't work either; but the hardware clock does...)

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi


python /home/pi/ZBA_Timelapse/shutdown.py
python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py

###python /home/ZBA_Timelapse/shutdown.py &
###(sleep 30; python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py) &

echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1_new_device
sudo hwclock -s

exit 0

EDIT:

I tried appending & to the end of the line per SlySven's answer, but it still does nothing. Both Python scripts are infinite loop programs, so I thought I'd try another approach: a shell script. The newly tried rc.local:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi

./home/pi/ZBA_Timelapse/startup.sh
echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1_new_device
sudo hwclock -s

exit 0

startup.sh looks like this:

#!/bin/bash/
sudo python /home/pi/ZBA_Timelapse/shutdown.py &
sudo python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py &

After both of those were set, I used sudo chmod +x /home/pi/ZBA_Timelapse/startup.sh to make startup.sh executable and rebooted. After reboot I used cd ZBA_Timelapse and ./startup.sh to successfully test the shell script. It worked great. Both Python scripts executed and worked like they should.

I still had no luck on auto-starting both Python scripts on boot. What am I doing wrong here?

Answer 1

Try:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi


python /home/pi/ZBA_Timelapse/shutdown.py &
python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py &

echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1_new_device
sudo hwclock -s

exit 0

The commented out code with the sleep might work better as:

python /home/ZBA_Timelapse/shutdown.py &
sleep 30 && python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py &

One point to note is "do either of the python scripts in /home/ZBA_Timelapse/ take input from stdin"? If so, they will stop when they get to that point, waiting in the background for input until they are brought back to the foreground - and as this is a non-interactive script run during multi-level startup - they will hang around for ever waiting for input that never comes...

Answer 2

Alright, thanks everyone for the suggestions in the other answers, but this is how I got it to work: I added python /home/pi/ZBA_Timelapse/startup.py to the rc.local, then I created a single python file that starts multiple python files in different threads.

This is what rc.local looks like:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi

python /home/pi/ZBA_Timelapse/startup.py

echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1_new_device
sudo hwclock -s

exit 0

This is what startup.py looks like:

import time
from threading
import os

def startprgm(i):
    print "Running thread %d" % i
    if (i == 0):
        time.sleep(1)
        print('Running: shutdown.py')
        os.system("sudo python /home/pi/ZBA_Timelapse/shutdown.py")
    elif (i == 1):
        print('Running: ZBA_Timelapse.py')
        time.sleep(1)
        os.system("sudo python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py")
    else:
        pass

for i in range(2):
    t = threasding.Thread(target=startprgm, args=(i,))
    t.start()

Obviously, I could increase the number of programs running by increasing i and adding another elif... It's not particularly pretty, but it works.

Answer 3

Use:

nohup python /home/pi/ZBA_Timelapse/shutdown.py >/dev/null 2>&1 &
nohup python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py >/dev/null 2>&1 &

This will pipe output to /dev/null (aka nowhere) and not create a nohup.out file.

Or you could try with "screen":

man screen

Your command should look like:

screen -d -m /home/pi/ZBA_Timelapse/ZBA_Timelapse.py

Answer 4

The environment variables inherited when init runs rc.local are different from the environment you have when you login.

This sounds like a candidate to be service, so learning about services would help you.

Answer 5

from threading import Thread
import time
import os


def startprgm(i):
    print "Running thread %d" % i
    if (i == 0):
        time.sleep(1)
        print('Running: shutdown.py')
        os.system("sudo python /home/pi/ZBA_Timelapse/shutdown.py")
    elif (i == 1):
        print('Running: ZBA_Timelapse.py')
        time.sleep(1)
        os.system("sudo python /home/pi/ZBA_Timelapse/ZBA_Timelapse.py")
    else:
        pass

for i in range(2):
    t = Thread(target=startprgm, args=(i,))
    t.start()