That shell script will get the path of the file needed to execute node, that is which node || which nodejs. You can't do what you want so what you do instead is run a shell script, hence the #!/bin/sh. (Apparently, sed could be used to replace tail Print file content without the first and last lines) I could've used a delimiter starting with // like dancek did, it would've worked but I find it cleaner to have only two lines at the beginning so I used tail -n +2 $0 to have the file read itself except the first two lines.ДЄnd if you run it in node, the first line is recognized as a shebang and ignored and the second is a one-line comment. 'which node || which nodejs' with backquotes instead of quotes launches node and the << feeds it whatever is on the right. Then, the right side of the first || gets evaluated. bin/false is the same thing as /bin/false except that the second slash transforms it into a comment for node, and that's why it's here. bin/false || `which node || which nodejs` << `tail -n +2 $0` Other people will be using sane shebangs anyway, so you're going to need that symlink.

Just use a symlink to apply common sense to your Debian-based systems, and then you can use a sane shebang. The package is called nodejs and it installs a binary called node. I don't know when Fedora provided a binary called nodejs, but I never saw it. This is only a problem on Debian-based systems, where policy overcame sense. Thanks to xavierm02 for inspiration and all the commenters for additional information! The subshell quits after the exec on second line is completed, so the rest of the file is never read by the shell. The rest of the file is just plain old javascript. Node.js just evaluates the string ':', which is like a no-op, and the rest of the line is parsed as a comment. The command substitution syntax $(.) isn't strictly Bourne, so opt for backticks if you run this in the 1980s. command -v is used instead of which for portability. The second line calls the shell no-op : with the argument // and then executes nodejs or node with the name of this file as parameter. Node.js bypasses any shebang that it finds, so this is a valid javascript file as far as Node.js is concerned. The first line is, obviously, a Bourne shell shebang. Child processes can be spawned by using our child_process.fork() API, and are designed to be easy to communicate with.The best I have come up with is this 'two-line shebang' that really is a polyglot (Bourne shell / Node.js) script: #!/bin/sh Node.js being designed without threads doesn't mean you can't take advantage of multiple cores in your environment. This makes Node.js well suited for the foundation of a web library or framework HTTP is a first-class citizen in Node.js, designed with streaming and low latency in mind. This behavior is like browser JavaScript - the event loop is hidden from the user Node.js exits the event loop when there are no more callbacks to perform. Node.js simply enters the event loop after executing the input script. In Node.js, there is no such start-the-event-loop call. Typically, behavior is defined through callbacks at the beginning of a script, and at the end a server is started through a blocking call like EventMachine::run(). In other systems, there is always a blocking call to start the event-loop. It presents an event loop as a runtime construct instead of as a library. Node.js takes the event model a bit further. Node.js is similar in design to, and influenced by, systems like Ruby's Event Machine and Python's Twisted. As an asynchronous event-driven JavaScript runtime, Node.js is designed to build scalable network applications

Shebang node js mac