[Hartford-pm] Re: [Boston.pm] sprintf sign handling question?

[Uri Guttman]

>>>>> "BM" == Bob Mariotti <r.mariotti at financialdatacorp.com> writes:

  BM> I have a perl program that extracts data from a report file.  Some of
  BM> the fields (columns) are monetary with a trailing sign (i.e:
  BM> 1,234.56-).
  BM> I extract the fields with the unpack function into scalars then strip
  BM> out the commas.  If the field ends with a '-' char then I subtract the
  BM> scalar from zero placing it back into itself.

why do you need a true negative number? it looks like all you are doing
is format stuff.

  BM> OK - I am getting what looks like a properly formatted file.  However,
  BM> I am having problems with sign handling.  Can anyone please offer
  BM> suggestions to help me arrive at the following:

  BM> input field:    1,234.56-
  BM> getting output:	-00123456
  BM> Desired output: 00123456-

what do you do if the number is positive? a trailing blank?
how long is the output field? i will assume 9 chars and padded with
leading 0's as you show above

this could do just that part if you want:

my $num = '1,234.56-' ;

$num =~ tr/,.//d ;

$out = substr( '0' x 9 . $num, -9, 9 ) ;


  BM> or preferably:  x'30303132333435d6' which is a zoned ascii decimal
  BM> field with a negating overstrike on the low order byte.

that is a little trickier but doable. again, i assume 8 bytes this time
and we have already stripped the exising - char. the number in use is
positive here but we know to mung the sign byte later.

	$out = sprintf( "%08d", $num ) | "\0" x 7 . "\xd0" ;

hope that helps,

uri

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