Re: COBOL Bit Manipulation

This may be the kind of routine Jon was referring to; I did not look at it in great detail.

http://www.simotime.com/cblbit01.htm

Scott

-----Original Message-----
From: cobol400-l-bounces@xxxxxxxxxxxx [mailto:cobol400-l-bounces@xxxxxxxxxxxx] On Behalf Of Jon Paris
Sent: Wednesday, January 12, 2011 2:23 PM
To: COBOL Programming on the iSeries/AS400
Subject: Re: [COBOL400-L] COBOL Bit Manipulation

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/
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