Re: Passing array to function

[Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx>]

Ignatius Reilly wrote on Fri, Sep 30, 2016 at 02:15:55 -0500:
> addtoarray() { [[ -d $1 ]] && myarray=($1 $myarray) }
> 
> which works as expected, prepending an element to an array only if its an
> existing directory.  I'd like to rewrite this function so that I can pass
> the array name as a parameter like so:
> 
> addtoarray /usr/foo myarray

You could do it with eval:

addtoarray() {
  [[ -d $1 ]] && eval "${(q)2}[1,0]=${(q)1}"
}

Explanation:

- The (q) are there to convert the values to command-line-quoted
  strings, for eval.  $2 probably needs no quoting — if it did, the eval
  would see a syntax error — but I put the (q) anyway to guard against
  invalid inputs (bobby tables attacks against the eval).

- After parameter substitution, the resultant string is:
    myarray[1,0]=/usr/foo
  which is a slice assignment that prepends an element to the named
  array.

If there's a solution without eval I'm sure someone will post it.

Cheers,

Daniel


> Thanks
>