Redirect standard input dynamically in a bash script

Question

I was trying to do this to decide whether to redirect stdin to a file or not:

[ ...some condition here... ] && input=$fileName || input=\"&0\"
./         


        

Answer 1

Standard input can also be represented by the special device file /dev/stdin, so using that as a filename will work.

file="/dev/stdin"
./myscript < "$file"