Koha/C4/Input.pm
2002-10-13 06:03:38 +00:00

170 lines
3.8 KiB
Perl

package C4::Input; #assumes C4/Input
# Copyright 2000-2002 Katipo Communications
#
# This file is part of Koha.
#
# Koha is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# Koha is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
# Suite 330, Boston, MA 02111-1307 USA
use strict;
require Exporter;
use vars qw($VERSION @ISA @EXPORT);
# set the version for version checking
$VERSION = 0.01;
=head1 NAME
C4::Input - Miscellaneous sanity checks
=head1 SYNOPSIS
use C4::Input;
=head1 DESCRIPTION
This module provides functions to see whether a given library card
number or ISBN is valid.
=head1 FUNCTIONS
=over 2
=cut
@ISA = qw(Exporter);
@EXPORT = qw(
&checkflds &checkdigit &checkvalidisbn
);
# FIXME - This is never used.
sub checkflds {
my ($env,$reqflds,$data) = @_;
my $numrflds = @$reqflds;
my @probarr;
my $i = 0;
while ($i < $numrflds) {
if ($data->{@$reqflds[$i]} eq "") {
push(@probarr, @$reqflds[$i]);
}
$i++
}
return (\@probarr);
}
=item checkdigit
$valid = &checkdigit($env, $cardnumber);
Takes a card number, computes its check digit, and compares it to the
checkdigit at the end of C<$cardnumber>. Returns a true value iff
C<$cardnumber> has a valid check digit.
C<$env> is ignored.
=cut
#'
sub checkdigit {
my ($env,$infl) = @_;
$infl = uc $infl;
my @weightings = (8,4,6,3,5,2,1);
my $sum;
my $i = 1;
my $valid = 0;
# print $infl."<br>";
# FIXME - for ($i = 1; $i < 8; $i++)
# or foreach $i (1..7)
while ($i <8) {
my $temp1 = $weightings[$i-1];
my $temp2 = substr($infl,$i,1);
$sum += $temp1 * $temp2;
# print "$sum $temp1 $temp2<br>";
$i++;
}
my $rem = ($sum%11);
if ($rem == 10) {
$rem = "X";
}
#print $rem."<br>";
if ($rem eq substr($infl,8,1)) {
$valid = 1;
}
return $valid;
} # sub checkdigit
=item checkvalidisbn
$valid = &checkvalidisbn($isbn);
Returns a true value iff C<$isbn> is a valid ISBN: it must be ten
digits long (counting "X" as a digit), and must have a valid check
digit at the end.
=cut
#'
#--------------------------------------
# Determine if a number is a valid ISBN number, according to length
# of 10 digits and valid checksum
sub checkvalidisbn {
use strict;
my ($q)=@_ ; # Input: ISBN number
my $isbngood = 0; # Return: true or false
$q=~s/x$/X/g; # upshift lower case X
$q=~s/[^X\d]//g;
$q=~s/X.//g;
if (length($q)==10) {
my $checksum=substr($q,9,1);
my $isbn=substr($q,0,9);
my $i;
my $c=0;
for ($i=0; $i<9; $i++) {
my $digit=substr($q,$i,1);
$c+=$digit*(10-$i);
}
$c=$c%11; # % is the modulus function
# FIXME - %=
($c==10) && ($c='X');
# FIXME - $isbngood = $c eq $checksum;
if ($c eq $checksum) {
$isbngood=1;
} else {
$isbngood=0;
}
} else {
# FIXME - Put "return 0 if $length($q) != 10" near the
# top, so we don't have to indent the rest of the function
# as much.
$isbngood=0;
} # if length good
return $isbngood;
} # sub checkvalidisbn
END { } # module clean-up code here (global destructor)
1;
__END__
=back
=head1 AUTHOR
Koha Developement team <info@koha.org>
=cut