Re: Perl Unpack Cobol Binary File and Fields

See: https://www.ibm.com/support/knowledgecenter/en/SS6SG3_4.2.0/com.ibm.entcobol.doc_4.2/PGandLR/concepts/cpari09.htm

PACKED-DECIMAL and COMP-3 are synonyms. Packed-decimal items occupy 1 byte of storage for every two decimal digits you code in the PICTURE description, except that the rightmost byte contains only one digit and the sign. This format is most efficient when you code an odd number of digits in the PICTURE description, so that the leftmost byte is fully used. Packed-decimal items are handled as fixed-point numbers for arithmetic purposes.

The digits are stored left-to-right as decimal numbers, two digits per byte. The rightmost nybble is a sign indicator ... unless SIGN IS SEPARATE.

https://www.ibm.com/support/knowledgecenter/en/SS6SG3_4.2.0/com.ibm.entcobol.doc_4.2/PGandLR/ref/rpari25.htm

Positive can be $C, $A, $E, $F; negative can be $D, $B. So the numeric value -(0)123 might be $000102030B.

Comment on Re: Perl Unpack Cobol Binary File and Fields

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Re^2: Perl Unpack Cobol Binary File and Fields by Anonymous Monk on May 06, 2020 at 13:33 UTC
so it turns out mike is a cobol expert. things make a little more sense now. :eyeroll:	[reply]
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Re^2: Perl Unpack Cobol Binary File and Fields by Anonymous Monk on May 04, 2020 at 22:01 UTC
See: https://www.ibm.com/support/knowledgecenter/SS6SG3_5.2.0/com.ibm.cobol52.ent.doc/PGandLR/ref/rlddepic.html The `V` symbol used in a PICTURE clause indicates the position of an assumed decimal point. This is not present in the data. So, the value `123.45` with `PIC 9(3)V99` might appear as `$01020304050C`. With a different picture, the identical data could be interpreted as `12345, 1.2345, 12.345` and so on.	[reply]