【shell】What does “< /dev/null” mean?

2>&1 < /dev/null 什么意思？

# openssl s_client -showcerts -connect 192.168.1.104:8443   </dev/null

What does “< /dev/null” mean?

https://unix.stackexchange.com/questions/230887/what-does-dev-null-mean

What does `<&-` do?

https://unix.stackexchange.com/questions/230330/what-does-do

What are the shell's control and redirection operators?

https://unix.stackexchange.com/questions/159513/what-are-the-shells-control-and-redirection-operators