Richard Lee wrote:
just trying to learn pack/unpack function in perl..
http://perldoc.perl.org/perlpacktut.html
You *should* have the documentation for Perl installed on your hard
drive which will be more relevant to the version of Perl you are using.
I thought i followed pretty much to the teeth from the tutorial itself
and when I type them into my linux box , it didn't exactly work the way
I expected them to.. What am I doing wrong?
[EMAIL PROTECTED] ~]# cat -A pack_test2.pl
cat -A? You're really trying to make it difficult to just copy and run
your code?
#!/usr/bin/perl$
$
use strict;$
use warnings;$
$
my $tot_income;$
my $tot_expend;$
use POSIX;$
$
my $date = POSIX::strftime("%m/%d/%Y", localtime);$
$
while (<DATA>) {$
my($date, $desc, $income, $expend) = unpack("A10 A27 A7 A*", $_);$
Your unpack() format defines the fields as:
01/24/2001 Ahmed's Camel Emporium 1147.99
01/28/2001 Flea spray 24.99
01/29/2001 Camel rides to tourists 235.00
^ ^ ^ ^
123456789012345678901234567890123456789012345678901234567890
The second field includes leading whitespace which you don't need. The
third field is not long enough and cuts off the decimal portion of the
number. The fourth field includes the decimal portion from the third
field which in numerical context will be interpreted as the fourth field
instead of the actual fourth field.
You probably want something like this instead:
unpack 'A11 A26 A9 A*', $_;
$tot_income += $income;$
$tot_expend += $expend;$
To suppress the "isn't numeric" warning you can do this:
$tot_income += $income || 0;
$tot_expend += $expend || 0;
print_this($tot_income,$tot_expend);$
}$
$
sub print_this {$
my($tot_income,$tot_expend) = @_;$
$tot_income = sprintf("%.2f", $tot_income); # Get them into $
$tot_expend = sprintf("%.2f", $tot_expend); # "financial" format$
print pack("A10 A27 A7 A*", $date, "Totals", $tot_income,
$tot_expend);$
And don't forget to add a newline at the end of each output line:
print pack( 'A10 A27 A7 A*', $date, 'Totals', $tot_income,
$tot_expend ), "\n";
}$
$
__END__$
01/24/2001 Ahmed's Camel Emporium 1147.99$
01/28/2001 Flea spray 24.99$
01/29/2001 Camel rides to tourists 235.00$
But it's not working out well..
[EMAIL PROTECTED] ~]# ./!$
./././././././pack_test2.pl
Argument "" isn't numeric in addition (+) at ./././././././pack_test2.pl
line 14, <DATA> line 1.
Argument "" isn't numeric in addition (+) at ./././././././pack_test2.pl
line 14, <DATA> line 2.
07/19/2008Totals 0.00
1147.9907/19/2008Totals 0.00
1172.9807/19/2008Totals 235.00 [EMAIL PROTECTED] ~]#
John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
http://learn.perl.org/
