This assumes the --option=value syntax which while a de-facto standard on Unix-like systems is unfortunately not supported by all programs.

I agree that system() (in C and other langues that simply copied it) is a bad API. For shell escaping a command to start a process with a list of arguments would be enough, and even POSIX C has you covered there with vararg and array variants. [1]

[1] http://man7.org/linux/man-pages/man3/posix_spawn.3.html (or fork() + exec())