Question

Is it possible to have a regex that is searching for a string like ‘\bfunction\b’ that will display the line number where it found the match?

Answer 1

I will suggest something that might work for you,

// Get a file into an array.  In this example we'll go through HTTP to get
// the HTML source of a URL.
$lines = file('http://www.example.com/');

// Loop through our array, show HTML source as HTML source; and line numbers too.
foreach ($lines as $line_num => $line) {
    // do the regular expression or sub string search here
}