You question isn't very clear to me, but if I understood you correctly I guess you could use a DOM parser to match the p tags and then check if any of them has the word "Washington" or if the phone number matches the Washington area.
EDIT: It appears as though the [anything] data in between the first set of numbers and 'washington' has to be a little more restrictive to work properly. The [anything] section should not contain any numbers, as, well, numbers are what we use to delimit the start of one of the addresses. This works for the three websites you gave us.
I'd say the best first step would be to strip out all HTML tags and replace the ' ' character entity:
$input = strip_tags($input);
$input = preg_replace("/ /"," ",$input);
then if the addresses match (close to) the format you specified, do:
$results= array();
preg_match("/[0-9]+\s+[^0-9]*?\s+washington,?\s*D\.?C\.?[^0-9]+[0-9]{5}/si",$input,$results);
foreach($result[0] as $addr){
echo "$addr<br/>";
}
This works for the three examples you provided, and $results[0] should contain each of the addresses found.
However, this won't work, for instance, if the address has an 'Apartment #2' or the like in it, because it assumes that the numbers closest to 'Washington, DC' mark the start of the address.
The following script matches each of the test cases:
<?php
$input = "
1433 Longworth House Office Building Washington, D.C. 20515
332 Cannon HOB Washington DC 20515
1641 LONGWORTH HOUSE OFFICE BUILDING WASHINGTON, DC 20515
1238 Cannon H.O.B.
Washington, DC 20515
8293 Longworth House Office Building • Washington DC • 20515
8293 Longworth House Office Building | Washington DC | 20515
";
$input = strip_tags($input);
$input = preg_replace("/ /"," ",$input);
$results= array();
preg_match_all("/[0-9]+\s+[^0-9]*?washington,?\s*D\.?C\.?[^0-9]*?[0-9]{5}/si",$input,$results);
foreach($results[0] as $addr){
echo "$addr<br/>";
}
This regex takes a more flexible approach towards what the input string can contain. The "Washington, DC" part has not been hard-coded into it. The different parts of the addresses are captured separately, the whole address will be captured in $matches[0].
$input = strip_tags($input);
preg_match('/
(\d++) # Number (one or more digits) -> $matches[1]
\s++ # Whitespace
([^,]++), # Building + City (everything up until a comma) -> $matches[2]
\s++ # Whitespace
(\S++) # "DC" part (anything but whitespace) -> $matches[3]
\s++ # Whitespace
(\d++) # Number (one or more digits) -> $matches[4]
/x', $input, $matches);
EDIT:
After looking at the sites you mentioned, I think the following should work. Assuming that you have the contents of the page you crawled in a variable called $page, then you could use
$subject = strip_tags($page)
to remove all HTML markup from the page; then apply the regex
(\d+)\s*(.*?)\s*washington.{0,5}(DC|D.C.).{0,5}(\d{5})
RegexBuddy generates the following code for this (I don't know PHP):
if (preg_match('/(\d+)\s*(.*?)\s*washington.{0,5}(DC|D.C.).{0,5}(\d{5})/si', $subject, $regs)) {
$result = $regs[0];
} else {
$result = "";
}
$regs[1] would then contain the contents of the first capturing parens (numbers), and so forth.
Note the use of the /si modifiers to make the dot match newlines, and to make the regex case-insensitive.