i had error using domxml_open_file

[crud_alex]

I had error using domxml_open_file for the below code, is the error doing with wrong configuration of PHP or apache, or is it doing with the code in fact?

Thanks in advance

regards

PHP file :

<?php

if(!$dom = domxml_open_file("example.xml")) {
echo "Error while parsing the document\n";
exit;
}

$root = $dom->document_element();
?>

"example.xml" :

<?php
$xmlstr = "<?xml version='1.0' standalone='yes'?>
<!DOCTYPE chapter SYSTEM '/share/sgml/Norman_Walsh/db3xml10/db3xml10.dtd'
[ <!ENTITY sp \"spanish\">
]>
<!-- lsfj -->
<chapter language='en'><title language='en'>Title</title>
<para language='ge'>
&amp;sp;
<!-- comment -->
<informaltable ID='findme' language='&amp;sp;'>
<tgroup cols='3'>
<tbody>
<row><entry>a1</entry><entry
morerows='1'>b1</entry><entry>c1</entry></row>
<row><entry>a2</entry><entry>c2</entry></row>
<row><entry>a3</entry><entry>b3</entry><entry>c3</entry></row>
</tbody>
</tgroup>
</informaltable>
</para>
</chapter>";
?>

[crud_alex]

<?php
$fh = fopen("example.xml", "r");
for($xml = '';$c = fgetc($fh), $c != ''😉{
$xml .= $c;
}

if(!$dom = domxml_open_mem($xml)) {
echo "Error while parsing the document\n";
exit;
}
print $dom->dump_mem();
?>

So please anyone can tell me why domxml_open_file isn't operating normally?

Thanks