Kód:
$fo = fopen( "data.txt", "r" );

$arr = file( "data.txt" );


function arrTrim( $arr, $term )
{
        foreach( $arr as $key => $val )
        {
                if( str_replace( "\n", "", $arr[ $key ] ) == $term )
                {
                        return TRUE;
                        continue;
                }
        }
        return FALSE;
}

print arrTrim( $arr, "aaaa" );
->