What is it good for? Why would you want to execute shell commands from JavaScript. If you already know the command, then why don't you just use the shell? Or wh

What is it good for? Why would you want to execute shell commands from JavaScript. If you already know the command, then why don't you just use the shell? Or why don't you just use JavaScript libraries/frameworks/whatevers if you can't make a shell script work but you know JavaScript?