4가지 실용적인 PHP 사용자 정의 함수 요약

function getOnlineIp() {
  $strOnlineIp = "";
  if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
    $onlineip = getenv('HTTP_CLIENT_IP');
  } elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
    $onlineip = getenv('HTTP_X_FORWARDED_FOR');
  } elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
    $onlineip = getenv('REMOTE_ADDR');
  } elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
    $onlineip = $_SERVER['REMOTE_ADDR'];
  }
  preg_match("/[\d\.]{7,15}/", $onlineip, $onlineipmatches);
  $strOnlineIp = $onlineipmatches[0] ? $onlineipmatches[0] : 'unknown';
  return $strOnlineIp;
}

function getStrTruncate($string, $length = 80, $etc = ''){
  if ($length == 0) return '';
  mb_internal_encoding("UTF-8");
  $string = str_replace("\n","",$string);
  $strlen = mb_strwidth($string);
  if ($strlen > $length) {
    $etclen = mb_strwidth($etc);
    $length = $length - $etclen;
    $str=''; $n = 0;
    for($i=0; $i<$length; $i++) {
      $c = mb_substr($string, $i, 1);
      $n += mb_strwidth($c);
      if ($n>$length) { break; }
      $str .= $c;
    }
    return $str.$etc;
  } else {
    return $string;
  }
}
echo getStrTruncate("博客",7); //结果是海底苍，utf8一个汉字对应二个字符

function timeFromNow($dateline) {
  if(emptyempty($dateline)) return false;
  $seconds = time() - $dateline;
  if ($seconds < 60){
    return "1分钟前";
  }elseif($seconds < 3600){
    return floor($seconds/60)."分钟前";
  }elseif($seconds < 24*3600){
    return floor($seconds/3600)."小时前";
  }elseif($seconds < 48*3600){
    return date("昨天 H:i", $dateline)."";
  }else{
    return date(&#39;Y-m-d&#39;, $dateline);
  }
}
echo timeFromNow(strtotime("2012-07-07 14:15:13")); //昨天 14:15
echo timeFromNow(strtotime("2012-07-08 14:15:13")); //1小前