What is a command to find priority of process in Linux?

awk '{print $18}' /proc/1337/stat (gets the prio for process 1337).

Other options:

Use ps -o pri. Specify the process id with -p 1337. Or, use -e to list all processes.

Experiment with this as a starting point if you want more than just the priority:

ps -e -o uid,pid,ppid,pri,ni,cmd

The top command lists the priority of running processes under the PR heading. If you have it installed, you can also search for a process and sort by priority in htop.

ps is probably the right way to go. You can then grep and awk your way to the relevant row and column