How to modify an attribute containing special characters in a xml file?

ankit.tayal560 has asked for the wisdom of the Perl Monks concerning the following question:

use strict;
use warnings;
use Data::Dumper;
use XML::DOM;

my $parser=new XML::DOM::Parser;
my $doc = $parser->parsefile('C:\perl\perl_tests\package.xml')or die$!
+;
my $root=$doc->getDocumentElement();

my $string="Johnson Controls Automotive Electronics&#xA;Package: GMLAN
+ 3.1 - Single Channel&#xA;Micro: uPD70F3524&#xA;Compiler: Green Hills
+ 5.1.7-CBD1110030";
my @package=$root->getElementsByTagName("package");

foreach my $package(@package)
{
if($package->getAttribute("name"))
{
my $name=$package->getAttribute("name");
print("$name\n");
$package->setAttribute("name",$string);
my $name_updated=$package->getAttribute("name");
print("$name_updated\n");
}
}
$doc->setXMLDecl($doc->createXMLDecl('1.0','UTF-8'));
$doc->printToFile("C:/perl/perl_tests/package.xml");





XML FILE :

<?xml version="1.0" encoding="UTF-8"?>
<ecuconfig id="1" name="ECU: IPC_LS" FrameworkVersion="1.4.48.0" Compa
+tibleVersion="1.4.0.0">
<package name="Johnson Controls Automotive Electronics Package: GMLAN 
+3.1 - Single Channel Micro: uPD70F3524 Compiler: Green Hills 5.1.7-CB
+D1110030" path="C:\Vector\CBD1110030_D04_V85x\Generators\Components\"
+>
<delivery version="09.01.22.01.11.00.30.04.00.00"/>
</package>
<package>
<delivery version="08.00.09.01.01.00.04.00.00.00"/>
</package>
</ecuconfig>





MODIFIED XML FILE AFTER RUNNING THIS SCRIPT :
<?xml version="1.0" encoding="UTF-8"?>
<ecuconfig id="1" name="ECU: IPC_LS" FrameworkVersion="1.4.48.0" Compa
+tibleVersion="1.4.0.0">
<package name="Johnson Controls Automotive Electronics&amp;#xA;Package
+: GMLAN 3.1 - Single Channel&amp;#xA;Micro: uPD70F3524&amp;#xA;Compil
+er: Green Hills 5.1.7-CBD1110030" path="C:\Vector\CBD1110030_D04_V85x
+\Generators\Components\">
<delivery version="09.01.22.01.11.00.30.04.00.00"/>
</package>
<package>
<delivery version="08.00.09.01.01.00.04.00.00.00"/>
</package>
</ecuconfig>
[download]

I've written above script to change the name attribute of package element as shown in $string but it is giving me some weird modified xml file idk why.! pretty confused.! can someone help me out with this? although the printed results in the cmd prompt are correct according to my script.

Comment on How to modify an attribute containing special characters in a xml file? Download Code

Replies are listed 'Best First'.
Re: How to modify an attribute containing special characters in a xml file? by Corion (Patriarch) on Sep 30, 2016 at 10:34 UTC
What do you expect? `&` is a special character in XML and a literal `&` needs to be encoded as `&` in XML. Maybe you did not want `&#xA` in your original string but something else?	[reply] [d/l] [select]
Re^2: How to modify an attribute containing special characters in a xml file? by ankit.tayal560 (Beadle) on Sep 30, 2016 at 11:07 UTC
ok got your point but I want that expression only in my string . any suggestions regarding how should I proceed??	[reply]
Re^3: How to modify an attribute containing special characters in a xml file? by Corion (Patriarch) on Sep 30, 2016 at 11:13 UTC
You will need to learn about ampersand-encoding and XML then. I guess that ` ` is already encoded and the ` ` stands for the character `\x0A` in Perl parlance. So you will need to change your initial string to: `my $string="Johnson Controls Automotive Electronics\x0APackage: GMLAN +3.1 - Single Channel\x0AMicro: uPD70F3524\x0ACompiler: Green Hills 5. +1.7-BD1110030";` [download] or, in a more sensible fashion: `my $string= join "\n", "Johnson Controls Automotive Electronics", "Package: GMLAN 3.1 - Single Channel", "Micro: uPD70F3524", "Compiler: Green Hills 5.1.7-BD1110030";` [download] I guess that the original text contains line breaks and you want to preserve them.	[reply] [d/l] [select]
Re^4: How to modify an attribute containing special characters in a xml file? by ankit.tayal560 (Beadle) on Sep 30, 2016 at 12:09 UTC
Re: How to modify an attribute containing special characters in a xml file? by jellisii2 (Hermit) on Sep 30, 2016 at 12:06 UTC
This question would lead me to post a handy reference for reserved characters in XML.	[reply]
Re: How to modify an attribute containing special characters in a xml file? by kcott (Archbishop) on Sep 30, 2016 at 11:12 UTC
G'day ankit.tayal560, I suspect your problem lies with backslashes in '`path=`' values; and, quite possibly, any other special characters in attribute values. As an example, consider '`path="...Components\"`', where '`\"`' means a literal quote and don't end the string; that should probably be '`\\"`', meaning a literal backslash followed by a quote to end the string. Take a look at quotemeta; note the '`\Q`' escape (which I personally use more often than the function). Also see these sections from perlop: Quote and Quote-like Operators Regexp Quote-Like Operators Quote-Like Operators Gory details of parsing quoted constructs Update: Added a missing quote: `\\"'` → `'\\"'` — Ken	[reply] [d/l] [select]
Re^2: How to modify an attribute containing special characters in a xml file? by ankit.tayal560 (Beadle) on Sep 30, 2016 at 11:41 UTC
already tried that. don't change a thing ! tried quoting & as \& also but dint worked!	[reply]
Re^3: How to modify an attribute containing special characters in a xml file? by kcott (Archbishop) on Sep 30, 2016 at 12:11 UTC
"... ! tried quoting & as \& also but dint worked!" Firstly, see ++Corion's response to you in this thread (to which you replied "ok got your point ..."). The code I posted in "Syntax-highlight Non-Perl Code for HTML" has, near the start: `{ my %entity_for = qw{& & < < > >}; sub chars_to_ents { $_[0] =~ s/([&<>])/$entity_for{$1}/gr } }` [download] You'll find usage near the end of the script. Perhaps you could write somethng like this tailored to your needs. — Ken	[reply] [d/l]