$file = 'data.txt';
$searchword = 'regular expression';
$content = file_get_contents($file);
$pattern = preg_quote($searchword, '/');
$pattern = "/(?i)^.*$pattern.*\$/m";
if (preg_match_all($pattern, $content, $matches)) {
echo "<pre>";
print_r($matches[0]);
echo "</pre>";
} else {
echo "Not found";
}
/*
data.txt
--------
Perform a php Regular Expression match
that is especially suited to web development.
Searches subject for a match to the regular expression
At least one element will be present within the array
component doesn't exist
Perform a global regular expression match
produced by The PHP Group
Split string by a REGULAR EXPRESSION
*/
/*
run:
Array
(
[0] => Perform a php Regular Expression match
[1] => Searches subject for a match to the regular expression
[2] => Perform a global regular expression match
[3] => Split string by a REGULAR EXPRESSION
)
*/
