in an ideal situation &,',",<,> etc should not be in the incoming XML. however i have run into some situations where this "bad" data has to be sent in and needs to be preserved from the incoming xml after it is parsed. But i cannot parse it with the reserved characters in it. I am having trouble running through the xml and converting the reserved characters: < to !40 etc. because it will convert all the < characters to !40. I need to break my xml apart so that i only call the convertchar function on the data elements of the xml and not on the tags themselves. 
$incoming_xml = '
<?xml version="1.0" encoding="UTF-8"?>
<TRANSACTION>
    <FIELDS>
        <FIELD KEY="user">name</FIELD>
        <FIELD KEY="password">pass&word</FIELD>
        <FIELD KEY="operation_type"><do_what></FIELD>
     </FIELDS>
</TRANSACTION>';

[download]
idea: split the incoming xml at the >DATA TO BE CONVERTED or WHITESPACE< and just call the convertchar method on the data between the >< I will need to be sure that i keep the xml syntax exactly how it should be. so based on my example $incoming_xml once the regex is run the converted xml should look like: 
$converted_xml = '
<?xml version="1.0" encoding="UTF-8"?>
<TRANSACTION>
    <FIELDS>
        <FIELD KEY="user">name</FIELD>
        <FIELD KEY="password">pass!38word</FIELD>
        <FIELD KEY="operation_type">!40do_what!41</FIELD>
     </FIELDS>
</TRANSACTION>';

[download]
once converted i will send it through XMLin then i can loop through the resulting hash and convert the !# back to their original values therefore preserving the necessary bad values.

i am having trouble creating a regex to do this though. Once again i appreciate all your help.

In reply to regex on XML by bear0053

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.