Comparing text blocks for similar content

Answer 1

if you need to compare this lists only once, i'd suggest converting docs to txt and then you'll be able to compare using regex. otherwise you'll need to use third party software to access info in the docs... like here maybe http://stackoverflow.com/questions/188452/reading-writing-a-ms-word-file-in-php

Answer 2

Create an array of both (possibly using the file() function, depending on the format of the text, or possibly just an explode() on content), and use array_diff().

Answer 3

$oldList = file('oldList.txt');
$newList = file('newList.txt');
$list = array_udiff($newList, $oldList, 'compare');

function compare($new, $old) {
    similar_text($old, substr($new, 3), $percent);
    return $percent >= 80 ? 0 : 1;
}

This is my basic idea. To find all texts similar by 80% and remove them from the $newList. You should adjust the percentage to satisfy your needs. The M/s is removed by substr($new, 3).

Answer 4

If there are no key fields for uniquely identifying the records, I think you will have to use something like similar_text or levenshtein.

$arOld = file('olddata.txt');
$arNew = file('newdata.txt');
foreach($arNew as $line){
   $line = trim(substr($line, 3));
   foreach($arOld as $old){
    similar_text($line, $old, $percentage);
    if ($percentage < 60){
        echo $line;
    }
   }
}

Answer 5

Try this

set_time_limit(500)
$arOld = file('olddata.txt');
$arNew = file('newdata.txt');
foreach($arNew as $line){
    if(substr($line, 0, 3) === 'M/s '){
        $line = trim(substr($line, 3));
        foreach($arOld as $old){
            similar_text($line, $old, $percentage);
            if ($percentage > 80){
                continue;
            }
        }
        echo $line;
    }
}