Re: AW: pvget, pvxget and pvxs interoperability and differences

[Peter Milne via Tech-talk <tech-talk at aps.anl.gov>]

Hello Malte

Bearing in mind Michael's comment that the CLI tools are a work in progress, this worked well for me:

Here's a Q:group table:
acq2206_088> pvget acq2206_588:SOE_LUT:TAB:Tbl | head
acq2206_588:SOE_LUT:TAB:Tbl
Row Event Pad PV_ID OFFSET_US
  0  1000   0  2000         0
  1  1001   0  2001         2
  2  1002   0  2002         4

Nice table-like render for the human client!

acq2206_088> pvxget acq2206_588:SOE_LUT:TAB:Tbl
acq2206_588:SOE_LUT:TAB:Tbl
    record._options.atomic bool = true
    labels string[] = {5}["Row", "Event", "Pad", "PV_ID", "OFFSET_US"]
    value.ROWNUM uint8_t[] = {64}[0,  ....

This is more like the "middleware developer edition" with ALL the info, but it gives a good clue how to pick off elements e.g. the first column :

acq2206_088> pvxget -r value.ROWNUM acq2206_588:SOE_LUT:TAB:Tbl | head
acq2206_588:SOE_LUT:TAB:Tbl
    value.ROWNUM uint8_t[] = {64}[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63]

So that works well!

ps: for Michael, the old caget tools seem to default to "client app developer mode", by default giving just what that developer really wants - the value.

e.g. repeat the above for a group of scalars:

acq2206_088> pvxget acq2206_588:SMPL | wc -l
154

154 lines : too much information!

The interesting bit for the "client app dev" :

acq2206_088> pvxget  acq2206_588:SMPL | head -n 3
acq2206_588:SMPL
    record._options.atomic bool = true
    AI_COUNT.value int32_t = 32

OK, so pvxget can pull this field by itself and this is good:
acq2206_088> pvxget -r AI_COUNT.value acq2206_588:SMPL | head -n 3
acq2206_588:SMPL
    AI_COUNT.value int32_t = 32


Hmm, but what I really want to see at a glance is  all the fields and their values, like this:

acq2206_088>  /usr/local/bin/pvget_value -t acq2206_588:SMPL
AI_COUNT      32
AI_INDEX       0
DI_COUNT       1
DI_INDEX      16
NSAM        1024
SP_COUNT      15
SP_INDEX      17
SSB          128

.. using wrapper script below to fake what perhaps "caget" would have done.

The wrapper is simple enough* of course, but it would be really helpful if that could be the "quick-look-see" default for the CLI tool itself.

* OK, after some googled sed/awk foo :-)

Cheers

Peter

acq2206_088> cat /usr/local/bin/pvget_value
#!/bin/sh

if [ -z $1 ]; then
	echo "USAGE pvget_value [-t] PV [PV]"
	exit 1
fi


if [ "$1" = "-t"  ];then
	shift
	pvget $* | sed -n  '/epics:nt/N;s/\n//p' | awk '{ printf("%-10s %5s\n", $2, $5) }'
else
	pvget $* | sed -n  '/epics:nt/N;s/\n//p'
fi






On 12/03/2026 10:20, Gotz, Malte via Tech-talk wrote:
> Hello Michael,
>
>   
>
> thank you for your quick reply. I totally understand that pv… and pvx… are
> not fully compatible and you do give ample warning, that the command line
> tools from pvxs are rather for testing. I mostly remarked on the
> discrepancies, because I also couldn’t find a definitive documentation on
> how to use that feature. Now, I know, this wasn’t just a failure of my
> search skills.
> As far as I understand it this explains the differences in some -r arguments
> working for pvxget but not for pvget and vice versa.
>
>   
>
> The more pressing issue for me is, that if I create an NT/Table group with
> QSRV2, I can’t retrieve a single column using pvget with any syntax. My
> understanding is that the client tool (pvget) should parse the string into
> some structure and send that via PVA to retrieve/request the data. The QSRV2
> on the other hand doesn’t need to parse the string I give with pvget -r,
> right?
>
> So, any idea what is going on here?
>
> Von: Michael Davidsaver <mdavidsaver at gmail.com>
> Gesendet: Mittwoch, 11. März 2026 21:48
> An: Gotz, Malte <malte.gotz at helmholtz-berlin.de>
> Cc: tech-talk at aps.anl.gov
> Betreff: Re: pvget, pvxget and pvxs interoperability and differences
>
>   
>
> On 3/11/26 7:53 AM, Michael Davidsaver wrote:
>
> PRs and issues open.
>
> I have created an additional issue specifically about pvRequest syntax
> interoperability
>
>   <https://urldefense.us/v3/__https://github.com/epics-base/pvxs/issues/156__;!!G_uCfscf7eWS!f0sfPQ_1pDgB3TagFQirbwsUOp7PTzmsJL80KGOvZX1tMydeM-p2l1koESeGKHw3fOLS3d2X6smPxXkf96vYrUNffsw$ >
> https://urldefense.us/v3/__https://github.com/epics-base/pvxs/issues/156__;!!G_uCfscf7eWS!f0sfPQ_1pDgB3TagFQirbwsUOp7PTzmsJL80KGOvZX1tMydeM-p2l1koESeGKHw3fOLS3d2X6smPxXkf96vYrUNffsw$ 
>
>   

--
Peter Milne
Director of Sales
https://urldefense.us/v3/__http://www.d-tacq.com__;!!G_uCfscf7eWS!f0sfPQ_1pDgB3TagFQirbwsUOp7PTzmsJL80KGOvZX1tMydeM-p2l1koESeGKHw3fOLS3d2X6smPxXkf96vY74y6Y2k$