convert the string

[sandy1028]

#!/usr/bin/perl
while($line = <DATA>){

@valid_entities= ('<a>','<abbr>','<acronym>','<br>');
my %htmlenties = map { $_ =>1 } @valid_entities;
#$line =~ s/(<\w*?>(?![^<\w*?>]*<\/\w*?>))/$1/g;
#$line =~ s/<\w*>(?![^<\/\w*>]*>)/&lt;/g;
$line =~  s/(<(\w*?)>)/exists $htmlenties{$1} ? $1 : defined ($2) ? "&lt;$2&gt;" : "&lt;"/eg;
print $line;
}

__DATA__
<helloe>How r u <a> www.google.com</a>
<hi>How r u </hi><et,-2><><br/>

How to convert character '<' to '&lt;'and '>' to &gt; for all the characters which is not present in the array and only if it doesnot have a closing end tag.In the above example,

the output should look like

&lt;helloe&gt;How r u <a> www.google.com</a>
<hi>How r u </hi>&lt;et,-2&gt;&lt;&gt;<br/>

[KevinR]

Where di you get that code from? It appears to already be using a hash (&#37;htmlenties) to check for valid html tags and perform the escaping if necessary. But there is no %htmlenties in the code you posted.

[sandy1028]

It is the hash to check whether string exists in an array.

I want the regular expression to check whether the tag has the closing tag

while($line = <DATA>){
$line =~ s/<(?![^<]*>)/&lt;/g;
print $line;
}

__DATA__
<helloe>How r u <a> www.google.com</a>
<hi>How r u </hi><et,-2><

For example, the above code checks for the ending '>'. If it doesnot exists it converts '<' to '&lt;'


In similar way to how check for the tag if it has the closing tag.
If it doesnot have, then convert < to &lt; and > to &gt;