Fixing bad data in a numeric field

 >> In specific these are packed fields that have a value of Hex'00' in
them.....

Well hex zeros are OK is all bytes of the packed field except the last <g>

First solution - if the whole field should be set to zero use
FIXNBR(*INPUTPACKED) on the H-spec.  Use this on every program that reads
the file.  If you suspect this was a one-time corruption, then write a
simple program using this specification and loop through the file
reading/writing every record.

If it is just the sign nibble that has the incorrect value, then the code
below (not tested but ..) will fix it simply for a 5 digit field.  Adjust
accordingly for other field lengths.

     D Fixup           DS
     D  TempPacked                    7p 2 Inz
     D  CharData                      3a   Overlay(Fixup)
     D                                1a   Overlay(Fixup:*Next)

     D Result          S              5p 0

     C                   Eval      CharData = InpData
      * CharData now has X'123450' - Fixup has X'1234500F'
     C                   Eval      Result = TempPacked
      * Result now has X'12345F'

This example assumes that the field InpData contains a valid packed number
(12345) _except_ that the sign is X'0' instead of X'F'.  The field in the
file is defined as character 3 and moved to the CharData field.  The unnamed
single character field that follows contains X'0F' by virtue of the fact
that it redefines the last byte of TempPacked which is initialized to zero.
Since TempPacked has two decimal places, when it is assigned to Result, the
lowest order nibbles will be discarded and the low order sign "attached" to
the integer portion of the number.

This technique is a modification of the method used to translate unsigned
packed fields imported from other platforms.

Jon Paris
Partner400