What is </dev/null in bash?

Question

In bash, standard (1) and error (2) output can be re-routed and discarded with:

>/dev/null 2>&1

But the following example does something different:

nohup myscript.sh >myscript.log 2>&1 </dev/null &

What is the meaning/function of </dev/null in the example above? In what sort of scripting scenario would it be useful?

(Example Source)

Answer 1

Redirecting /dev/null to stdin will give an immediate EOF to any read call from that process. This is typically useful to detach a process from a tty (such a process is called a daemon). For example, when starting a background process remotely over ssh, you must redirect stdin to prevent the process waiting for local input.

Another reason to redirect to /dev/null is to prevent an unused file descriptor being created for stdin. This can minimize the total open file handles when you have many long running processes.