How to only run a command in .bash_profile if its not already running?

Question

Goal:
Run socat only once.
I'm trying to expose docker web services via TCP. On macOS/linux these services are bound to a unix socket. The following command accomplishes the task:

socat -d TCP-LISTEN:2376,range=127.0.0.1/32,reuseaddr,fork UNIX:/var/run/docker.sock

So I don't have to remember to type this all the time, I'd like it to start when the computer starts. I don't know how to accomplish that particular goal, but I have done a little bit of work with .bash_profile. So I'll settle for running socat whenever a terminal runs. However, since .bash_profile runs for every terminal instance, I'd like a mechanism that only runs the command if it's not already running. But I don't know how to check, from .bash_profile if something is already running. Can you help?

Answer 1

If you want that command to start at boot then you can just use a cronjob.

As root:

crontab -e

Next, enter the following just like you would in a text editor:

@reboot /usr/bin/socat -d TCP-LISTEN:2376,range=127.0.0.1/32,reuseaddr,fork UNIX:/var/run/docker.sock

That tells crontab to run your command when the system boots. Make sure that there is a new line following the command by pressing ENTER after it. Enter :wq! just like you would in vim to save it.

Reboot your system and then grep for the command to make sure that it's running.

ps aux | grep socat