How to set process ID in Linux for a specific program

Question

I was wondering if there is some way to force to use some specific process ID to Linux to some application before running it. I need to know in advance the process ID.

Answer 1

On CentOS7.2 you can simply do the following:

Let's say you want to execute the sleep command with a PID of 1894.

sudo echo 1893 > /proc/sys/kernel/ns_last_pid; sleep 1000

(However, keep in mind that if by chance another process executes in the extremely brief amount of time between the echo and sleep command you could end up with a PID of 1895+. I've tested it hundreds of times and it has never happened to me. If you want to guarantee the PID you will need to lock the file after you write to it, execute sleep, then unlock the file as suggested in Ruslan's answer above.)