RE: [SNL] possibility to cut the argument string.

["Laznovsky Michael \(PSI\) via Tech-talk" <tech-talk@aps.anl.gov>]

Hi- I can think of at least two ways of doing what you want; one a standard feature of SNL, and the

other a "weird trick".

 

#1: Use "pvAssign" in a loop, with generated PV names (as shown below):

https://www-csr.bessy.de/control/SoftDist/sequencer/search.html?q=pvassign

 

#2: Dynamic arg string: if the macro names and values are easily generated as suggested in

the original post, you could write a separate SNL wrapper program which builds the arg string

at runtime and then calls your program with it, for example (macro & variable declarations

omitted):

 

      program run_myExample ( ... meta-macros? ... )

      ss run_myExample

      {

        state doit {

          when (1) {

 

              %% extern struct seqProgram seqmyExample;    // ref to your SNL program

 

              %% static char args[ ARGBUF_SIZE ];    // arg buffer: should be large enough to hold

                                                     // full final string

              args[0] = '\0';

              for ( n = 1; n <= N; n++ ) {           // append macros for devices 1..N

 

                %% sprintf(

                %%      &args[ strlen(args) ],

                %%      "%smacro%d=MyExp:MyDevice-%02d:Unit",

                %%      (n > 0)? "," : "",

                %%      n,n );

              }

 

              %% seq( & seqmyExample, args, STACK_SIZE );  // start your main SNL program; seq is

                                                           // just another function, after all

            } state done

        }

 

        state done {

          when (delay(999999)) {} state done         // delay forever (or maybe exit?)

        }

      }

 

Then in the startup script just run "seq &run_myExample" instead of the original.  You could also add

macros to the wrapper to generate different PV names, as you suggest.

 

Example compiles but not tested, but I use basically this method to start a variable number of per-device

seq threads based on the runtime contents of in-memory EPICS DBs.

 

cheers

Mike

https://www.psi.ch

 

 

 

 

 

From: tech-talk-bounces@aps.anl.gov <tech-talk-bounces@aps.anl.gov> On Behalf Of GAGET Alexis via Tech-talk
Sent: Montag, 15. April 2019 17:22
Subject: [SNL] possibility to cut the argument string.

 

Dear All,

I have a SNL sequence with a lot of macro, i find the call in the iocshell really not readable

i.e :

seq myExample “macro1=MyExp:MyDevice-01:Unit, macro2=MyExp:MyDevice-02:Unit, macro3=MyExp:MyDevice-03:Unit, macro4=MyExp:MyDevice-04:Unit….To infinity and beyond”

 

Is there any way to maybe cut the string ?

i.e :

seq myExample “macro1=MyExp:MyDevice-01:Unit”+

“macro1=MyExp:MyDevice-02:Unit”+

“macro2=MyExp:MyDevice-03:Unit”+

“ macro3=MyExp:MyDevice-04:Unit”+

“….To infinity and beyond”

(of course it doesn’t work, I’ve tried different possibility but I haven’t found… maybe it’s obvious

 

I want my sequence as much generic as possible, so substitutions macros offers a good possibility to call differents PVs.

 

If it’s not possible yet, is it possible to maybe create an issue somewhere to ask the feature ?

 

Thanks for your help.

...

Alexis GAGET

CEA Saclay - DRF/Irfu/DIS/LDISC

alexis.gaget@cea.fr