Double to Packed decimal conversion in Mainframe 'C'

sampaul4u · New User Joined: 27 Mar 2010 Posts: 19 Location: folirida

Hi,
Could anyone assist me to write a function in IBM "C" to convert Double value to Packed Decimal format?

Please advise me.

Thanks.

Bill O'Boyle · Posted: Fri Sep 17, 2010 4:30 pm

What do you mean by "Double" value? Is this a doubleword (8-bytes)? Are the field contents binary? Are the field contents display-numeric?

What language is the program that needs to invoke this Function?

More information is needed....

Bill

sampaul4u · New User Joined: 27 Mar 2010 Posts: 19 Location: folirida

I need this in C laguage. Double precision value (Ex 1000.11) needs to be converted to Packed decimal format (that is eaqualent to COBOL COMP-3)

Thanks.

enrico-sorichetti · Posted: Fri Sep 17, 2010 4:53 pm

why should we

You did not even care to look at the manuals

start from
publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/Shelves/CBCBS180 ( for example )
and search for DECIMAL and PACKED

after having read the manuals, if there is something not clear, somebody will be glad to help

Bill O'Boyle · Posted: Fri Sep 17, 2010 4:57 pm

Is this a management directive or is this your suggestion to management?

This can be done easily in a "Called" Assembler sub-program, using the "grande" instructions or in COBOL or PL/I for that matter.

Why must it be "C"?

Have you tried "Googling" this?

Bill

Ian McIntosh · New User Joined: 01 Sep 2011 Posts: 1 Location: Canada

IBM mainframe C has a family of builtin packed decimal types, equivalent to COBOL COMP-3. The declaration syntax is
_Decimal (total_digits) varname;
or
_Decimal (total_digits, digits_after_decimal_point) varname;
and if you include <decimal.h> you can use decimal instead of _Decimal.

The operations on the decimal types are mostly the same as for other numeric types. Literals end with the suffix "D". Use "%D(total_digits, digits_after_decimal_point)" in printf and scanf.

To convert a double to decimal, just use an assignment statement or a cast.

double d = 123.456;
_Decimal (6,3) dd;
dd = d;
or
dd = (_Decimal(6,3)) d;

For more information, see
publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/CBCLR170/3.3.4?SHELF=CBCBS180&DT=20070601155844

edited to fix a wrong URL

dick scherrer · Posted: Fri Sep 02, 2011 10:47 am

Hello and welcome to the forum,

Thanks for posting this info.

Enjoy your time here and hopefully we will have things you find useful as well

d