OT: Bash arrays & indirection?

[Ian Malone]

On 16 February 2012 08:43, Patrick Lists <fedora-list at puzzled.xs4all.nl> wrote:
> Hi,
>
> I am trying to do the following in bash:
>
> OPTIONS = ( alfa beta gamma )
> SUBOPTIONS_alfa = ( alfa0 alfa1 )
> count=0
> SETCOUNT = ${#SUBOPTIONS_${OPTIONS[$count]}[@]}
>
> The SETCOUNT line gives a substitution error. I would like the
> ${OPTIONS[$count]} to be substituted with alfa so SETCOUNT is:
>
> SETCOUNT = ${#SUBOPTIONS_alfa[@]} which should equal 2.
>
> Anyone have an idea how I can make this work? Quick and dirty is fine. I
> have already been told that it should be done differently. I appreciate that
> but right now I just want to make it work.
>

Pushing the limits of what can be done with bash, it's just about
possible. As you mention this is the point you should consider
translating to another language. Anyway...

http://stackoverflow.com/questions/4582137/bash-indirect-array-addressing

Also N.B. shouldn't be any spaces around those equals signs in your example.

OPTIONS=( alfa beta gamma )
SUBOPTIONS_alfa=( alfa0 alfa1 )
SUBOPTIONS_beta=( beta_1 )
SUBOPTIONS_gamma = ( gamma_1 gamma_2 gamma_3 )
count=0
#then...
for count in {0..2} ; do
nameSUBOPTS=SUBOPTIONS_${OPTIONS[$count]}[@]
tmpARR=(${!nameSUBOPTS}) #You need tmpARR, because the '#' expansion
wont work with '!'
SETCOUNT=${#tmpARR[@]}
echo ${OPTIONS[$count]}:$SETCOUNT
done

Finally, it's spelt 'alpha' ;)

-- 
imalone