GnuCOBOL Knowledge Base
Problem With Obscure “P” (Scaling) Picture Symbol in Packed Decimal
A technical note on GnuCOBOL handling of the P scaling character in packed-decimal variables.
The development of the Camelian GnuCOBOL Debugging Extensions has
uncovered problems in GnuCOBOL’s handling of the P scaling
character in PICTURE strings for
PACKED DECIMAL (COMP-3 and
COMP-6) variables. This is an OBSCURE
capability originally introduced to save a few bytes of storage for
numbers in the thousands, millions, thousandths, millionths, etc. Where
the numeric-edited value correctly uses P, the
positions containing the P character(s) is supposed to
ALWAYS be ZERO.
At present, in certain cases, GnuCOBOL stores incorrect data into the
underlying storage location of variable. That data is then is neither
stored on output or displayed correctly. In some cases, displayed values
are truncated do to NULL characters (x”00”) in storage.