View Category
XML
Parsing

Process an XML document

Given the XML Document:

<shopping>
  <item name="bread" quantity="3" price="2.50"/>
  <item name="milk" quantity="2" price="3.50"/>
</shopping>

Print out the total cost of the items, e.g. $14.50
perl
#! /usr/bin/perl
# -*- Mode: CPerl -*-

use strict;
use XML::Simple;
use Data::Dumper;

# Given the XML Document:
#
# <shopping>
# <item name="bread" quantity="3" price="2.50"/>
# <item name="milk" quantity="2" price="3.50"/>
# </shopping>
#
# Print out the total cost of the items, e.g. $14.50

my $xml =
" <shopping>\n"
." <item name=\"bread\" quantity=\"3\" price=\"2.50\"/>\n"
." <item name=\"milk\" quantity=\"2\" price=\"3.50\"/>\n"
." </shopping>\n";

my $xs = XML::Simple->new();
my $ref = $xs->XMLin($xml);
my $stuff = ${$ref}{item};

my $q;
my $p;
my $t;
my $z;

foreach my $item ( sort keys %{$stuff}){
$q = ${$stuff}{$item}{quantity};
$p = ${$stuff}{$item}{price};
$z = $q*$p;
printf "%5.5s %2d @\$%5.2f = \$%5.2f\n",$item,$q,$p,$z;
$t += $z;
}
printf "Total \$%5.2f\n",$t;

#eos
use strict;
use XML::Twig;

use Data::Dumper;

my $xml = <<ENDXML;
<shopping>
<item name="bread" quantity="3" price="2.50"/>
<item name="milk" quantity="2" price="3.50"/>
</shopping>
ENDXML

my $xt = XML::Twig->parse( $xml );

my $price;
foreach my $item ($xt->root->children('item')) {
$price += ($item->{att}{price} * $item->{att}{quantity})
}

printf "Total Cost: %.2f\n", $price


Creation

create some XML programmatically

Given the following CSV:

bread,3,2.50
milk,2,3.50

Produce the equivalent information in XML, e.g.:

<shopping>
  <item name="bread" quantity="3" price="2.50" />
  <item name="milk" quantity="2" price="3.50" />
</shopping>
perl
#! /usr/bin/perl
# -*- Mode: CPerl -*-

use strict;
use XML::Simple;
use Data::Dumper;

# bread,3,2.50
# milk,2,3.50
#
# Produce the equivalent information in XML, e.g.:
#
# <shopping>
# <item name="bread" quantity="3" price="2.50" />
# <item name="milk" quantity="2" price="3.50" />
# </shopping>
#

my $line;
my $item;
my $q;
my $p;
my $z;

my $xs = XML::Simple->new();
my %d = ();
while($line=<DATA>){
chomp $line;
($item,$q,$p) = split ",",$line;
$d{shopping}{item}{$item}{quantity} = $q;
$d{shopping}{item}{$item}{price} = $p;
}

$xml = $xs->XMLout(\%d, KeepRoot => 1);
print $xml,"\n";

__DATA__
bread,3,2.50
milk,2,3.50
use strict;
use XML::Writer;
use Text::CSV;

my $csv = <<ENDOFCSV;
bread,3,2.50
milk,2,3.50
ENDOFCSV

open my $fh, '<', \$csv or die "Can't open string, $!\n";
my $csv = Text::CSV->new;
my $writer = XML::Writer->new(DATA_MODE => 1, DATA_INDENT => 2);

$writer->startTag('shopping');

while (my $arr_ref = $csv->getline($fh)) {
my %attributes;
@attributes{qw/name quantity price/} =
@{$arr_ref}[0..2];
$writer->emptyTag('item' => %attributes)
}
$writer->endTag('shopping');