I'm working on an Ultimate Plus r83 virtual machine running on AIX.
I'm working on a project that requires me to feed a file to a
Mainframe COBOL environment. They have a predefined layout that
requires two COMP type fields and a COMP-3 field. The COBOL
definition for the COMP-3 field is S9(7) COMP-3.

I'm able to accomplish the COMP-3 packing, but I'm losing any required
zero fill at the beginning of my field. here's an example.

MYVAR = '15000'
MYOUT = ICONV(MYVAR,'MP'); *this packs the "15000" into a comp-3
field, but it doesn't know that my field def is S9(7)

So, instead of HEX data that looks like
0100
050F

I get the following:
100
50F

I tried zero padding MYVAR

MYVAR = '15000' 'R%7'
MYOUT = ICONV(MYVAR,'MP')

but it drops the leading zeroes.

If i try to append anything to the front, it just adds ASCII
characters.

Has anyone had to tackle this previously?

Try the routine found at:
http://pata-group.com
At the bottom of the page see:
"Convert signed number to COMP-3 format".
The result is byte ordered left to right but the order might be
different on the target machine.
Test program:
DEFFUN COMP3()

A = -1500 ;* Number to convert
SIZE = 4 ;* S9(7) length in bytes

X = COMP3(A,SIZE)
PRINT OCONV(X,'MX')
STOP

In your example, you're doing field formatting prior to the ICONV
function.


MYVAR = '15000' 'R%7'
MYOUT = ICONV(MYVAR,'MP')

What you say that you want is a packed field with leading zeros. The
size is 4.

MYIN = 15000 ;* FOR CLARITY
MYVAR = ICONV(MYIN,'MP) ;* PACK THE FIELD
MYOUT = MYVAR 'R%4' ;* FORMAT IT RIGHT JUSTIFIED IN 4 ZEROS

depending on your compiler you could do this

MYOUT = ICONV(15000,'MP')'R%4'

I've not worked on Ultimate since about 1985...

Always format your data AFTER you process it. Formatting is part of
the output phase.

Good Luck!

On 2010-11-03 13:42:04 -0400, Bill Crowell <bcrowell (AT) pavuk (DOT) com> said:

That's fine to get an ASCII string formatted as described, but I
believe he needs COMP-3 encoding, which Lucian seems to have provided a
link to some code that will do it.

--
Kevin Powick

On Nov 3, 1:42*pm, Bill Crowell <bcrow... (AT) pavuk (DOT) com> wrote:
Bill I tried that one. The problem that I ran into was that the
"padding" was in ascii, it wasn't packed.


I think I can make Lucian's stuff work, but this compiler is flat out
rotten and doesn't like to use DEFFUN. I can work around that
though. Thanks for all of the help guys.

I was a fairly regular contributor to this group about 10 years ago.
I thought it had died. I was extremely happy to see that people are
still out here.

I've changed the code so now is a subroutine that works on ancient
compilers too.
http://pata-group.com

A = -123 ;* Number to convert
SIZE = 4 ;* S9(7) length in bytes
CALL COMP3(A,B,SIZE)
PRINT OCONV(B,'MX')