<?php
$str = <<<EOS
05start
いちご
バナナ
うめ
もも
05finish
12start
ごはん
おそば
12finish
15start
わかめ
ひじき
めかぶ
15finish
18start
コーヒー
ココア
18finish
EOS;
 
$str = str_replace(array("\r\n", "\r"), "\n", $str);
 
preg_match_all('/^(\d{2})start\n([\S\s]*)\n\1finish$/m',$str,$matches);
 
$data = array();
 
for($i = 0; $i < count($matches[1]); $i++) {
   $key = $matches[1][$i];
   $value = str_replace("\n", ' ', $matches[2][$i]);
   $data[$key] = $value;
}
print_r($data);
?>
 

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