Question

How would I go about printing a process id before the process is actually executed? Is there a way I can get the previously executed process id and just increment?

i.e.

printf(<process id>);
execvp(process->args[0], process->args);

Answer 1

exec family of syscalls preserve current PID, so just do:

if(fork() == 0) {
    printf("%d\n", getpid());
    execvp(process->args[0], process->args);
}

New PIDs are allocated on fork(2), which returns 0 to child process and child process’ PID to parent.