How to open a "-" dashed filename using terminal?

you can use redirection

cat < -file_name

This type of approach has a lot of misunderstanding because using - as an argument refers to STDIN/STDOUT i.e dev/stdin or dev/stdout .So if you want to open this type of file you have to specify the full location of the file such as ./- .For eg. , if you want to see what is in that file use cat ./-

Both cat < - and ./- command will give you the output

It looks like the rev command doesn't treat - as a special character.

From the man page

The rev utility copies the specified files to standard output, reversing the order of characters in every line.

so rev - | rev

should show what's in the file in the correct order.