Command added to rc.local has no effect

Question

In some post here, I read that if I wanted to run a shell script at start up, I would have to add it at the end of /etc/rc.local but before exit 0. However, when I do this it seems to have no effect. Specifically, I am using my Pi3 as a Access Point and for some reason, I always have to sudo service hostapd restart after boot to make it work. Adding this line to /etc/rc.local does not have the same effect. Where can I add this line so it really only executes after everything else has loaded?

Here are the contents of /etc/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

sudo service hostapd restart

exit 0

Answer 1

If those articles you're using predate systemd, be aware that rc.local compatibility is provided via a systemd service. On a fresh install, you will see a "Start /etc/rc.local Compatability" boot message if you're running newer versions of raspbian.

After modifying /etc/rc.local, check the status of the service with sudo systemctl status rc-local. You may see a warning that your must run sudo systemctl daemon-reload.

Depending on what you run in /etc/rc.local, the startup order may not be correct. In this case, if you need to ensure the order of startup (e.g. hostapd only after networking is fully up), then creating a proper systemd service will be required.

Note that some of this may vary depending on whether you upgraded to stretch or did a fresh install, or on what else you've installed.

This article on U&L SE may be useful for replacing /etc/rc.local with a systemd equivalent. There is a good discussion on the RPi forums noting that it is executed, but early in the boot process, likely before networking is available.

In short, you want to create and enable a systemd service file to launch things in the proper sequence during boot.

Answer 2

Check out the line that says:

sudo nano service hostapd restart

It's opening nano, it should be:

sudo service hostapd restart

Edit:

From here:

If your command runs continuously (perhaps runs an infinite loop) or is likely not to exit, you must be sure to fork the process by adding an ampersand to the end of the command, like so:

I don't think that it's your problem, but try it, maybe it will work:

sudo service hostapd restart &