Shell Programming and Scripting

So this should be correct:

Code:

N=$[2+i]
y=echo "${!N}"

Also, about:

Code:

N=$[2+i]

Shouldn't it be

Code:

$[2+$i]?

Thanks

Why are you putting 'echo' in there? It's not necessary. I just used 'echo' as an example -- the positional parameter gets fed into echo instead of the number itself.

When I say $((N+2)), I don't mean $[$N+2], I mean $((N+2)). I would do what I posted, word for word, letter for letter, keystroke for keystroke.

Code:

N=$((2+i))
y=${!N}

I've never heard of that shell syntax before.

BASH seems to accept it, but KSH doesn't:

Code:

$ A=1
$ echo $[2+$A]
[2+1]
$

$(( )) works fine in both. So $(( )) is better for portable code.