Assign regex pattern as key to an array - php

Question

I have an array of regular expressions and am trying to loop through a text document to find the first pattern, assign that as the key to an array then continue through find the second pattern and assign that as the value. Whenever I come across pattern 1 I want that to always be assigned as a key and all pattern 2 matches that follow until I come across a new key will be assigned to that first key as values.
Text document structure:
Subject: sometext
Email: someemail#email.com
source: www.google.com www.stackoverflow.com www.reddit.com
So I have an array of expressions:
$expressions=array(
'email'=>'(\b[a-zA-Z0-9._%+-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}\b)',
'url'=>'([A-Za-z][A-Za-z0-9+.-]{1,120}:[A-Za-z0-9/](([A-Za-z0-9$_.+!*,;/?:#&~=-])|%[A-Fa-f0-9]{2}){1,333}(#([a-zA-Z0-9][a-zA-Z0-9$_.+!*,;/?:#&~=%-]{0,1000}))?)'
);
I want to loop through my text document and match the email address then assign that as the key to an array then assign all urls that follow as the values, s the output to the above text would be:
array(
'someemail#email.com' => array (
0 => 'www.google.com',
1 => 'www.stackoverflow.com',
2 => 'www.reddit.com'
)

Answer 1

One way to do such a thing:
$parts = preg_split("/(emailexpr)/",$txt,-1,PREG_SPLIT_DELIM_CAPTURE);
$res = array();
// note: $parts[0] will be everything preceding the first emailexpr match
for ( $i=1; isset($parts[$i]); $i+=2 )
{
$email = $parts[$i];
$chunk = $parts[$i+1];
if ( preg_match_all("/domainexpr/",$chunk,$match) )
{
$res[$email] = $match[0];
}
}
replace emailexpr and domainexpr with your regexp gibberish.

Answer 2

I would do:
$lines = file('input_file', FILE_SKIP_EMPTY_LINES);
$array = array();
foreach($lines as $line) {
if(preg_match('/^Subject:/', $line) {
$email = '';
} elseif(preg_match('/^Email: (.*)$/', $line, $m)) {
if(preg_match($expressions['email'], $m[1])) {
$email = $m[1];
}
} elseif(preg_match('/^source: (.*)$/', $line, $m) && $email) {
foreach(explode(' ', $m[1]) as $url) {
if(preg_match($expressions['url'], $url)) {
$array[$email][] = $url;
}
}
}
}