How can I use Perl regular expressions to parse XML data?

Posted by Luke on Stack Overflow See other posts from Stack Overflow or by Luke
Published on 2010-06-01T14:36:43Z Indexed on 2010/06/01 14:53 UTC
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Filed under:

Xml

|

regex

|

perl

I have a pretty long piece of XML that I want to parse. I want to remove everything except for the subclass-code and city. So that I am left with something like the example below.

EXAMPLE

TEST SUBCLASS|MIAMI

CODE

<?xml version="1.0" standalone="no"?>  
<web-export>  
<run-date>06/01/2010  
<pub-code>TEST  
<ad-type>TEST  
<cat-code>Real Estate</cat-code>  
<class-code>TEST</class-code>  
<subclass-code>TEST SUBCLASS</subclass-code>  
<placement-description></placement-description>  
<position-description>Town House</position-description>  
<subclass3-code></subclass3-code>  
<subclass4-code></subclass4-code>  
<ad-number>0000284708-01</ad-number>  
<start-date>05/28/2010</start-date>  
<end-date>06/09/2010</end-date>  
<line-count>6</line-count>  
<run-count>13</run-count>  
<customer-type>Private Party</customer-type>  
<account-number>100099237</account-number>  
<account-name>DOE, JOHN</account-name>  
<addr-1>207 CLARENCE STREET</addr-1>  
<addr-2> </addr-2>  
<city>MIAMI</city>  
<state>FL</state>  
<postal-code>02910</postal-code>  
<country>USA</country>  
<phone-number>4014612880</phone-number>  
<fax-number></fax-number>  
<url-addr> </url-addr>  
<email-addr>[email protected]</email-addr>  
<pay-flag>N</pay-flag>  
<ad-description>DEANESTATES2BEDS2BATHSAPPLIANCED</ad-description>  
<order-source>Import</order-source>  
<order-status>Live</order-status>  
<payor-acct>100099237</payor-acct>  
<agency-flag>N</agency-flag>  
<rate-note></rate-note>  
<ad-content> MIAMI&#47;Dean Estates&#58; 2 
beds&#44; 2 baths&#46; Applianced&#46; Central air&#46; Carpets&#46; Laundry&#46; 2 decks&#46; Pool&#46; Parking&#46; Close to everything&#46;No smoking&#46; No utilities&#46; &#36;1275 mo&#46; 401&#45;578&#45;1501&#46;  </ad-content>  
</ad-type>  
</pub-code>  
</run-date>  
</web-export>

PERL

So what I want to do is open an existing file read the contents then use regular expressions to eliminate the unnecessary XML tags.

open(READFILE, "FILENAME");  
while(<READFILE>)  
{  
$_ =~ s/<\?xml version="(.*)" standalone="(.*)"\?>\n.*//g;  
    $_ =~ s/<subclass-code>//g;  
    $_ =~ s/<\/subclass-code>\n.*/|/g;  
    $_ =~ s/(.*)PJ RER Houses /PJ RER Houses/g;  
    $_ =~ s/\G //g;  
    $_ =~ s/<city>//g; 
    $_ =~ s/<\/city>\n.*//g;  
    $_ =~ s/<(\/?)web-export>(.*)\n.*//g;  
    $_ =~ s/<(\/?)run-date>(.*)\n.*//g;  
    $_ =~ s/<(\/?)pub-code>(.*)\n.*//g;  
    $_ =~ s/<(\/?)ad-type>(.*)\n.*//g;  
    $_ =~ s/<(\/?)cat-code>(.*)<(\/?)cat-code>\n.*//g;  
    $_ =~ s/<(\/?)class-code>(.*)<(\/?)class-code>\n.*//g;  
    $_ =~ s/<(\/?)placement-description>(.*)<(\/?)placement-description>\n.*//g;  
    $_ =~ s/<(\/?)position-description>(.*)<(\/?)position-description>\n.*//g;  
    $_ =~ s/<(\/?)subclass3-code>(.*)<(\/?)subclass3-code>\n.*//g;  
    $_ =~ s/<(\/?)subclass4-code>(.*)<(\/?)subclass4-code>\n.*//g;  
    $_ =~ s/<(\/?)ad-number>(.*)<(\/?)ad-number>\n.*//g;  
    $_ =~ s/<(\/?)start-date>(.*)<(\/?)start-date>\n.*//g;  
    $_ =~ s/<(\/?)end-date>(.*)<(\/?)end-date>\n.*//g;  
    $_ =~ s/<(\/?)line-count>(.*)<(\/?)line-count>\n.*//g;  
    $_ =~ s/<(\/?)run-count>(.*)<(\/?)run-count>\n.*//g;  
    $_ =~ s/<(\/?)customer-type>(.*)<(\/?)customer-type>\n.*//g;  
    $_ =~ s/<(\/?)account-number>(.*)<(\/?)account-number>\n.*//g;  
    $_ =~ s/<(\/?)account-name>(.*)<(\/?)account-name>\n.*//g;  
    $_ =~ s/<(\/?)addr-1>(.*)<(\/?)addr-1>\n.*//g;  
    $_ =~ s/<(\/?)addr-2>(.*)<(\/?)addr-2>\n.*//g;  
    $_ =~ s/<(\/?)state>(.*)<(\/?)state>\n.*//g;  
    $_ =~ s/<(\/?)postal-code>(.*)<(\/?)postal-code>\n.*//g;  
    $_ =~ s/<(\/?)country>(.*)<(\/?)country>\n.*//g;  
    $_ =~ s/<(\/?)phone-number>(.*)<(\/?)phone-number>\n.*//g;  
    $_ =~ s/<(\/?)fax-number>(.*)<(\/?)fax-number>\n.*//g;  
    $_ =~ s/<(\/?)url-addr>(.*)<(\/?)url-addr>\n.*//g;  
    $_ =~ s/<(\/?)email-addr>(.*)<(\/?)email-addr>\n.*//g;  
    $_ =~ s/<(\/?)pay-flag>(.*)<(\/?)pay-flag>\n.*//g;  
    $_ =~ s/<(\/?)ad-description>(.*)<(\/?)ad-description>\n.*//g;  
    $_ =~ s/<(\/?)order-source>(.*)<(\/?)order-source>\n.*//g;  
    $_ =~ s/<(\/?)order-status>(.*)<(\/?)order-status>\n.*//g;  
    $_ =~ s/<(\/?)payor-acct>(.*)<(\/?)payor-acct>\n.*//g;  
    $_ =~ s/<(\/?)agency-flag>(.*)<(\/?)agency-flag>\n.*//g;  
    $_ =~ s/<(\/?)rate-note>(.*)<(\/?)rate-note>\n.*//g;  
    $_ =~ s/<ad-content>(.*)\n.*//g;  
    $_ =~ s/\t(.*)\n.*//g;  
    $_ =~ s/<\/ad-content>(.*)\n.*//g;  
}  
close( READFILE1 );

Is there an easier way of doing this? I don't want to use any modules. I know that it might make this easier but the file I am reading has a lot of data in it.

Developer IT