On Wed, Dec 19, 2018 at 10:31:36PM -0500, Bize Ma wrote:
> It is also interesting that this fails:
>
> var=hello; echo "${var[ ~0]}"
> bash: var: bad array subscript
>
> Isn't `var[0]` valid and equivalent to `var` ?
Yes, but ~0 is not 0.
wooledg:~$ echo $(( ~0))
-1
The issue you're reporting appears to be present in arithmetic contexts
in general, not only arrays:
wooledg:~$ echo $((~0))
bash: /home/wooledg: syntax error: operand expected (error token is
"/home/wooledg")
It appears that bash is performing tilde expansion when there's no
whitespace in front of the tilde, or bitwise negation if there is
whitespace.
