- If the function called is `posix_spawnp`, and the passed program name **does not** contain a slash, the path is used unmodified, and the path to the directory containing the program on $PATH is prepended to the program's path and assigned to `argv[0]. If the program name **does** contain a slash, the path is absolutised relative to CWD, and assigned to argv[0]
- If the function called is `posix_spawn`, the behaviour is as described above in the case where path contains a slash
* Add initial tests
R Aadarsh