Syntax for a single-line Bash infinite while loop

Question

I am having trouble coming up with the right combination of semicolons and/or braces. I\'d like to do this, but as a one-liner from the command line:

while [         


        

Answer 1

while true; do foo; sleep 2; done

By the way, if you type it as a multiline (as you are showing) at the command prompt and then call the history with arrow up, you will get it on a single line, correctly punctuated.

$ while true
> do
>    echo "hello"
>    sleep 2
> done
hello
hello
hello
^C
$  while true; do    echo "hello";    sleep 2; done