Add string on each line of a file content before or after the content. Just insert the file to be processed on the same directory in our server and call our script via browser.

add-text.php

<?php
$handle = fopen("file.txt", "r");
if ($handle) {
    while (($line = fgets($handle)) !== false) {
        // process the line read.
        echo "Text Before - " . $line . " - Text After<br>";
    }

    fclose($handle);
} else {
    echo "Error!<br>";
} 

?>