How to verify if nginx is running or not?

Question

Looking at the requirement you have, the below command shall help:

service nginx status

This is probably system-dependent, but this is the simplest way I've found.

if [ -e /var/run/nginx.pid ]; then echo "nginx is running"; fi

That's the best solution for scripting.

You could use lsof to see what application is listening on port 80:

sudo lsof -i TCP:80

If you are on mac machine and had installed nginx using

brew install nginx

then

brew services list

is the command for you. This will return a list of services installed via brew and their corresponding status.

The modern (systemctl) way of doing it:

systemctl is-active nginx

You can use the exit value in your shell scripts as follows:

systemctl -q is-active nginx && echo "It is active, do something"