Richard Lee wrote: > > just trying to learn pack/unpack function in perl.. > > http://perldoc.perl.org/perlpacktut.html > > 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 > #!/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*", $_);$ > $tot_income += $income;$ > $tot_expend += $expend;$ > 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, > $tot_expend);$ > }$ > $ > __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] ~]#
I think you're spacing your data out with tab characters. A tab is a single character as far as unpack is concerned so things are getting mis-aligned. The "Argument isn't numeric" warnings are because the income and expenditure fields are blank. If you want the to default to zero you need to write defined and /\S/ or $_ = 0 for $tot_income, $tot_expend; after the unpack. You know that a literal space in the unpack pattern is ignored? If you want to skip over a character use 'x'. HTH, Rob -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
