python脚本不会在启动ubuntu时运行

Question

I try to run my python scrip at startup but it doesn't work.

Here is my python script(doesn't work):

#!/usr/bin/env python

import paho.mqtt.publish as publish
from datetime import datetime

t = str(datetime.now())
print t
with open("/home/james/mqtt/log.txt", "a+") as f:
    f.write("it works " + t + "\n")

Here is my python script(works):

#!/usr/bin/env python

from datetime import datetime

t = str(datetime.now())
print t
with open("/home/james/mqtt/log.txt", "a+") as f:
    f.write("it works " + t + "\n")

Here is my rc.local files(also try crontab and setting up service in /ect/init.d):

#!/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.

# /bin/mqtt_test.py &
# mosquitto_sub -t "mqtt"

/home/james/mqtt/script.sh
# /etc/mqtt/mqtt_test.py

exit 0

It look like by importing paho.mqtt.publish can make my script stop working, I am new to Linux, I have no idea why. Can someone help me out? Thanks for your help.

Ubuntu 16.04

Let me know if you need more info.

Answer 1

I have faced this problem myself. For me the problem was path. I could get it working by using a shell script to launch a python script and launch the shell script from crontab.

Here is my launcher.sh . You may not use sudo if you do not want. home/pi/record_data is the path where my file resides.

cd /
cd home/pi/record_data
sudo python record_video.py

In this case record_video.py is the python file I want to run at startup. In the crontab edit, I added this line below.

@reboot sh /home/pi/record_data/launcher.sh &

Do try this out if it work for you :) Good luck. I have not got the logging the error into files working yet though.

Answer 2

it looks to me like you need to set/change the write permissions of the file before your python scrypt do this:

f.write("it works " + t + "\n")

for you is working because (maybe you are the owner of the file).

typical linux file permission is described as:

do use the chmod with the property flags, so linux has the rights to write the file too, please refer to the ubuntu help :)