Re: COBOL Bit Manipulation

[Jason Abreu <jason.abreu@xxxxxxxxxxxxxxxxxxxx>]

I realize that the PIC 1 clause is for display usage only.  It was just 
the first thing that had come to mind.

I can get this:

01        WORK.
  05      CHAR        PIC  X(01)  VALUE X'00'.
  05      BIN         REDEFINES   CHAR
                      PIC  9(01)  COMP-3.

But the question is still how to do bit manipulation to set a specific 
bit to "on" or "off."

I do not know any RPG and, due to in-house coding standards, am looking 
for a COBOL solution.  Ideally, I would be able to redefine a binary 
data type into bits and use 88-level items to turn them on or off.

Thanks,

Jason Abreu
Abreu Innovations, Inc.
jason.abreu@xxxxxxxxxxxxxxxxxxxx
http://www.abreuinnovations.com/

On 1/12/2011 3:19 PM, Jon Paris wrote:
> Well Pic 1 means a single byte indicator so that won't help.
>
> It is years since I did this but in the pre-ILE days I did it with a simple divide/multiply routine. Don't have a sample of the code handy but it is not hard to do. Depending on what you want, you can either divide by the appropriate power of 2 to shift the bit in question to the least significant position, then divide by 2 to isolate the bit in question (in the remainder) change that value as you wish and reverse the process.
>
> If you want to test/set any arbitrary bit then it is easier to just use a divide by 2 loop and store the remainders in an array. Test/change as desired and rebuild by a repetitive multiply loop.
>
> These days I would code it in RPGIV and use the bit oriented functions in RPG IV to do the work. Then call the RPGIV routine form the COBOL code - probably much easier.
>
>
> Jon Paris
>
> www.Partner400.com
> www.SystemiDeveloper.com
>
>
>
> On Jan 12, 2011, at 2:59 PM, Jason Abreu wrote:
>
> > Does anybody have experience with bit manipulation in COBOL?
> >
> > I would like to be able to switch individual bits on/off in a single byte.
> >
> > I imagined something like:
> >
> > 01        WORK.
> >    05      CHAR-BYTE      PIC X(01)    VALUE X'40'.
> >    05      BINARY-REP     REDEFINES    CHAR-BYTE.
> >      10    BIT-1          PIC 1.
> >        88  BIT-1-ON                    VALUE B'1'.
> >        88  BIT-1-OFF                   VALUE B'1'.
> >      ... repeat for all 8 bits.
> >
> >
> > So usage could be something like
> >
> > SET BIT-1-ON TO TRUE.
> > MOVE CHAR-BYTE TO FILE-FIELD.
> >
> > Any ideas on this?
> > Thanks, ahead of time!
> > --
> > Jason Abreu
> > Abreu Innovations, Inc.
> > jason.abreu@xxxxxxxxxxxxxxxxxxxx
> > http://www.abreuinnovations.com/
> > --
> > This is the COBOL Programming on the iSeries/AS400 (COBOL400-L) mailing list
> > To post a message email: COBOL400-L@xxxxxxxxxxxx
> > To subscribe, unsubscribe, or change list options,
> > visit: http://lists.midrange.com/mailman/listinfo/cobol400-l
> > or email: COBOL400-L-request@xxxxxxxxxxxx
> > Before posting, please take a moment to review the archives
> > at http://archive.midrange.com/cobol400-l.