php scandir for given $q search query

i have search values like "search value" (defined as $q) and .txt files called "search value.txt" in /mydir/ directory. How can i scandir /mydir/ for the search value ($q) and put the found .txt file with php include command into page? Or is it a better way to put $q value into php file_get_contents php code (i mean put them together like a txt filename like (q$.txt - searchvalue.txt somehow) and pull the content of the .txt file into page? If yes, how? Thanks in advance.

Suppose you have this directory structure :

mydir
  --file1.tx
  --file2.tx
index.php

index.php

$filepath = glob("mydir/*.txt");//read all txt files in data directory
//print_r($filepath);//debug purpose
$search = 'file1';

// Browse all files and search the $search string in filenames
foreach ($filepath as $filename) {

    // Give us file name only without the extension
    $fileNameOnly = basename($filename, '.txt');

    // Check if a file name only contains exactly our keyword $search
    $isExactMatch = preg_match("/\b".$search."\b/iu", $fileNameOnly);

    if ( $isExactMatch ) {
      // Include the .txt file as result
      require $filename;
    }
}

Tested, it does the trick.