Re: eval varylen = *blanks

Jack wrote:
>Hello Everybody!
>
>I ran into an odd problem (at least I think it is odd) a couple of days ago.
>I was making some program changes using variable length fields in RPGIV.
>The changes included using eval and *blanks to initialize the variable.
>When I tried to run the program, it crashed.  I used debug to see what was
>going on because the code looked good to me and I was surprised to find that
>eval  varylen = *blanks resulted in a value of '############## for varylen
>instead of '              '.  I modified it to use the move opcode instead
>and it worked.  I then tried, unsuccessfully, to see if this "peculiarity?"
>is documented anywhere.  Has anyone else run across this before?  Am I the
>only one who thinks that this is weird?

There are a few details missing from your description, so it's
hard to answer your question.

Here's how it's supposed to work:  EVAL VAR=*BLANKS  sets the
field to all blanks.  If VAR is defined as char 20 varying,
you get 20 blanks and the current length of the variable is
set to the maximum.  (Another way to set a character varying
field to blanks is to first set the length to 0, then to the
desired number of blanks.)

Using MOVE is different in that the current length doesn't
change.  If the result variable is currently 10, you get those
10 chars set to blanks.  (ie. For the fixed-format opcodes,
the length of a character varying field stays fixed.)

If you're using V4R2 or V4R3, note that the debugger doesn't
handle character varying type properly, so what you see there
may not be correct.

If you want to mimic the MOVE behavior using EVAL, you could
code:  EVAL  %SUBST(VAR:1) = *BLANKS

Cheers!  Hans

Hans Boldt, ILE RPG Development, IBM Toronto Lab, boldt@ca.ibm.com


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