It’s how all new processes in Unix are created. There is no “spawn new process running this code” operation. Instead:

(1) you duplicate yourself with fork()

(2) the parent process continues about its business

(3) the created process calls execve() to become something else

This is the mechanism by which all new processes are created, from init (process 1) to anything you run from your shell.

Real life examples here, in this example of a Unix shell:

https://github.com/mirror/busybox/blob/master/shell/ash.c

Bash is probably the best example of this style of working. You have a shell process that forks and spawns child processes from itself that are turned into whatever program you've called from your terminal.

see here: https://pubs.opengroup.org/onlinepubs/9699919799/functions/e...

plenty of basic examples with execv, execve, execvp, etc.

if the execv() call succeed then it completely replaces the program running in the process that calls it

you can do plenty of tricks with that ;)