Re: subArray behavior reading just 1 element

["Johnson, Andrew N. via Tech-talk" <tech-talk at aps.anl.gov>]

Hi Lucas,

On Sep 1, 2021, at 4:16 PM, Lucas Russo <lerwys at gmail.com> wrote:

lerwys@lerwysPC:~$ caget wave

wave 5 1 2 3 4 5
lerwys@lerwysPC:~$ caget subarr
subarr 5 2 0 0 0 0

subarr always returns an array of 5 elements, but I was trying to achieve a subArray of only 1 element. Something like:

lerwys@lerwysPC:~$ caget subarr
subarr                         2

Is that possible?

Try using caget -c subarr instead — unfortunately caget without a -c option will always print the maximum number of elements that the array can hold (zero-filled after the number received), but using -c it uses a CA get_callback() API which asks the IOC how many elements the array currently holds and shows that instead. That will be 1 so you should get what you’re asking for.

- Andrew

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Complexity comes for free, simplicity you have to work for.