trigger node js file

Problem

I have a JS file that runs via node.js, so normally I crank open a terminal window and type something like node myfile.js and it runs and runs all day; fun.

Then when I want to reboot it, I hit control-c and and it quits. Then I can run the command again.

Now what I would like to do is be able to do this through a web page so that my users can run specific JS files and also be able to "reboot" them.

So two questions about this:

  1. Is it possible, and if so how do I get started?
  2. Is it safe, and if not, can it be made safe?

Based on swatkins response

i tried this and got nothing

 $output = exec("node -v");
 echo $output;

then i tried on my local machine and it worked fine what gives ?

also I'm still not sure about the security and the ability to stop a running script

Problem courtesy of: mcgrailm

Solution

Assuming you're on Unix-based OS:

You can run shell commands via the exec() function:

// in php file
// to start the script 
exec("node myscript.js &", $output);

$output becomes an array of each line of output, so you can see what the process id is. Then you would use that process id to kill the script:

exec("kill " . $processid);
Solution courtesy of: swatkins

Discussion

I would avoid any direct interaction with the shell. It would probably be the safest, to solve it this way:

  • implement some overall "service"-script, that launches the user-node-app and keeps it running (something like https://github.com/isaacs/node-supervisor)
  • Make it, so it automatically reboots on changes of either the relevant files or a database-entry
  • With the user triggering a reboot, add a flag (timestamp?) to the database-entry or file that is watched by the reboot-script. It then will reboot the node.js-app/script.
Discussion courtesy of: lucorlis

This recipe can be found in it's original form on Stack Over Flow.