Jeans & Development コンピューターのことなどを綴ったメモ (旧：目から鱗 w/SQLite)

/////////////////////////////////////
// functions url_head & url_exists //
// ver 0.10 by katsumi             //
/////////////////////////////////////
function url_head($myUrl,&$myStatus,&$myHeader){
  //check URL and resolve host, port and URI
  if (substr($myUrl,0,7)!='http://') return false;
  $myUri=substr($myUrl,7);
  if (($i=strpos($myUri,'/',0))===false) return false;
  $myPort=80;
  $myHost=substr($myUri,0,$i);
  $j=strpos($myUri,':',0);
  if ((!($j===false)) && ($j<$i))
  {
    $myPort=(int)substr($myUri,$j+1,$i-$j-1);
    $myHost=substr($myUri,0,$j);
  }
  $myUri=substr($myUri,$i);

  //get header information from browser
  $headers = apache_request_headers();
  while (list($header, $value) = each ($headers)) {
    switch (strtolower($header)) {
    case 'accept':
      $accept=$value;
      break;
    case 'accept-language':
      $acceptlanguage=$value;
      break;
    case 'user-agent':
      $useragent=$value;
      break;
    default:
      break;
    }
  }

  //create header for HTTP request
  $t="HEAD $myUri HTTP/1.0\r\n";
  $t=$t."Conection: Close\r\n";
  $t=$t."Accept: $accept\r\n";
  $t=$t."Accept-Language: $acceptlanguage\r\n";
  $t=$t."User-Agant: $useragent\r\n";
  $t=$t."Host: $myHost\r\n";
  $t=$t."\r\n";

  //obtain HEAD information
  $myStatus=0;
  if (!($fp = @fsockopen($myHost,$myPort, $errno, $errstr, 30))) return false;
  fwrite($fp,$t);
  $t='';
  while (!feof($fp))
  {
    $t=fgets($fp,1024);
    if (substr($t,strlen($t)-2)=="\r\n") $t=substr($t,0,strlen($t)-2);
    if (substr($t,0,5)=='HTTP/')
    { // "HTTP/1.1 200 OK" or something like this
      if (($i=strpos($t,' ',0))===false) continue;
      if (($j=strpos($t,' ',$i+1))===false) continue;
      $myStatus=(int)substr($t,$i+1,$j-$i-1);
    } else { // headers
      if (($i=strpos($t,': ',0))===false) continue;
      $myHeader[substr($t,0,$i)]=substr($t,$i+2);
    }
  }
  fclose($fp);
  if ($myStatus===0) return false;
  if ($myStatus>=400) return false;
  return true;
}
function url_exists($myUrl){
  return url_head($myUrl,$myStatus,$myHeader);
}