php - grab matching words out of the search string -

im trying pull matching words out of search string via $_get['kw']; function. if person write "i+want+use+google", script display "google"(only when word "google" inside txt ), if write "i+want+yahoo+to+use", display "yahoo"(because "yahoo" inside txt), , if write "i+want+to+say+hello+to+dr.google", script display "hello dr.google" because inside txt have "hello dr.google" have "google" inside our query should match "hello dr.google" looking exact matches...and echo function use in multiple places triger word $match_term.
in txt file words grouped this(everything without "." , /./ |.| ):

google
yahoo
hello dr.google
other
other
other
othe.r

and file big on 5000 words found bigger files funcion:"fget" better use...
searched multiple q&a in stackoverflow exact query match function didnt found im looking for.
qestion: how proper code should like?
far found code not looking longer strings...

<?php $file = 'somefile.txt'; $searchfor = $_get['kw'];   // file contents, assuming file readable (and exist) $contents = file_get_contents($file); // escape special characters in query $pattern = preg_quote($searchfor, '/'); // finalise regular expression, matching whole line $pattern = "/^.*$pattern.*\$/m"; // search, , store matching occurences in $matches if(preg_match_all($pattern, $contents, $matches)){    echo "found matches:\n";    echo implode("\n", $matches[0]); } else{    echo "no matches found"; }