This is a tiny wrapper around javascript package managers, in your project you can write rnpm start and it will list all the scripts that contain the word start like this:
Then you can select the script you want to run, hit Enter and it will figure it out if you're using npm, yarn or pnpm and run the script with the correct package manager.
If there's only one matching script it will run that immediately.
USAGE: rnpm [FLAGS] [OPTIONS] [script]
FLAGS:
- -h, --help Prints help information
- -r, --run-exact If set, immediately run the script that matches exactly.
- -V, --version Prints version information
OPTIONS
- -m, --manager [possible values: npm, yarn, pnpm]
ARGS:
- <script> The string you're searching for
Running rnpm --help gives you the same output as above.