Re: destructuring assignment

[Bart Schaefer <schaefer@brasslantern.com>]

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On Mon, Feb 3, 2014 at 10:00 AM, Peter Stephenson
<p.stephenson@samsung.com>wrote:

> On Mon, 03 Feb 2014 18:36:00 +0100
> Roman Neuhauser <neuhauser@sigpipe.cz> wrote:
> > having an array such as
> >
> >   declare -a partitions; partitions=(
> >     /boot:boot:512:fat:boot,legacy_boot
> >     :swap:10240:swap
> >     /:root:-:btrfs
> >   )
>

If you were to put a trailing colon on the partitions with no mount flags,
you'd have the same number of colons in each array element, which might
make some other things easier (as PWS mentioned).

>   for mountp name size fs flags in ...; do
>

Given the trailing colons to create empty flags fields for the lines that
do not have flags, you can do

    for mountp name size fs flags in "${(@s.:.)${(j.:.)partitions}}"

However, I'd still prefer Peter's nested loops.


> for line in $partitions; do
>   for mountp name size fs flags in "${(@s.:.)line}"; do
>     print mountp=$mountp name=$name size=$size fs=$fs flags=$flags
>   done
> done
>

Another option is

while IFS=: read mountp name size fs flags; do
  # ...
done <<<${(F)partitions}

That should work even without the trailing colons, but could be tricky if
you need standard input inside the loop body.