有用的php函数

<?php

/**

* 获取客户端IP

* @return [string] [description]

*/

function getClientIp() {

$ip = NULL;

if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {

 $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);

 $pos = array_search('unknown',$arr);

 if(false !== $pos) unset($arr[$pos]);

 $ip = trim($arr[0]);

}elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {

 $ip = $_SERVER['HTTP_CLIENT_IP'];

}elseif (isset($_SERVER['REMOTE_ADDR'])) {

 $ip = $_SERVER['REMOTE_ADDR'];

}

// IP地址合法验证

$ip = (false !== ip2long($ip)) ? $ip : '0.0.0.0';

return $ip;

}

/**

* 获取在线IP

* @return String

*/

function getOnlineIp($format=0) {

global $S_GLOBAL;

if(empty($S_GLOBAL['onlineip'])) {

 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);

 $S_GLOBAL['onlineip'] = $onlineipmatches[0] ? $onlineipmatches[0] : 'unknown';

}

if($format) {

 $ips = explode('.', $S_GLOBAL['onlineip']);

 for($i=0;$i<3;$i++) {

  $ips[$i] = intval($ips[$i]);

 }

 return sprintf('%03d%03d%03d', $ips[0], $ips[1], $ips[2]);

} else {

 return $S_GLOBAL['onlineip'];

}

}

/**

* 获取url

* @return [type] [description]

*/

function getUrl(){

$pageURL = 'http';

if (isset($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on") {

$pageURL .= "s";

}

$pageURL .= "://";

if ($_SERVER["SERVER_PORT"] != "80") {

$pageURL .= $_SERVER["HTTP_HOST"] . ":" . $_SERVER["SERVER_PORT"] . $_SERVER["REQUEST_URI"];

} else {

$pageURL .= $_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"];

}

return $pageURL;

}

/**

* 获取当前站点的访问路径根目录

* @return [type] [description]

*/

function getSiteUrl() {

$uri = $_SERVER['REQUEST_URI']?$_SERVER['REQUEST_URI']:($_SERVER['PHP_SELF']?$_SERVER['PHP_SELF']:$_SERVER['SCRIPT_NAME']);

return 'http://'.$_SERVER['HTTP_HOST'].substr($uri, 0, strrpos($uri, '/')+1);

}

/**

* 字符串截取，支持中文和其他编码

* @param [string] $str  [字符串]

* @param integer $start [起始位置]

* @param integer $length [截取长度]

* @param string $charset [字符串编码]

* @param boolean $suffix [是否有省略号]

* @return [type]   [description]

*/

function msubstr($str, $start=0, $length=15, $charset="utf-8", $suffix=true) {

if(function_exists("mb_substr")) {

 return mb_substr($str, $start, $length, $charset);

} elseif(function_exists('iconv_substr')) {

 return iconv_substr($str,$start,$length,$charset);

}

$re['utf-8'] = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";

$re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";

$re['gbk'] = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";

$re['big5'] = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";

preg_match_all($re[$charset], $str, $match);

$slice = join("",array_slice($match[0], $start, $length));

if($suffix) {

 return $slice."…";

}

return $slice;

}

/**

* php 实现js escape 函数

* @param [type] $string [description]

* @param string $encoding [description]

* @return [type]   [description]

*/

function escape($string, $encoding = 'UTF-8'){

$return = null;

for ($x = 0; $x < mb_strlen($string, $encoding);$x ++)

{

$str = mb_substr($string, $x, 1, $encoding);

if (strlen($str) > 1) { // 多字节字符

 $return .= "%u" . strtoupper(bin2hex(mb_convert_encoding($str, 'UCS-2', $encoding)));

} else {

 $return .= "%" . strtoupper(bin2hex($str));

}

}

return $return;

}

/**

* php 实现 js unescape函数

* @param [type] $str [description]

* @return [type]  [description]

*/

function unescape($str) {

$str = rawurldecode($str);

preg_match_all("/(?:%u.{4})|.{4};|&#\d+;|.+/U",$str,$r);

$ar = $r[0];

foreach($ar as $k=>$v) {

 if(substr($v,0,2) == "%u"){

  $ar[$k] = iconv("UCS-2","utf-8//IGNORE",pack("H4",substr($v,-4)));

 } elseif(substr($v,0,3) == "") {

  $ar[$k] = iconv("UCS-2","utf-8",pack("H4",substr($v,3,-1)));

 } elseif(substr($v,0,2) == "&#") {

  echo substr($v,2,-1)."";

  $ar[$k] = iconv("UCS-2","utf-8",pack("n",substr($v,2,-1)));

 }

}

return join("",$ar);

}

/**

* 数字转人名币

* @param [type] $num [description]

* @return [type]  [description]

*/

function num2rmb ($num) {

$c1 = "零壹贰叁肆伍陆柒捌玖";

$c2 = "分角元拾佰仟万拾佰仟亿";

$num = round($num, 2);

$num = $num * 100;

if (strlen($num) > 10) {

 return "oh,sorry,the number is too long!";

}

$i = 0;

$c = "";

while (1) {

 if ($i == 0) {

  $n = substr($num, strlen($num)-1, 1);

 } else {

  $n = $num % 10;

 }

 $p1 = substr($c1, 3 * $n, 3);

 $p2 = substr($c2, 3 * $i, 3);

 if ($n != '0' || ($n == '0' && ($p2 == '亿' || $p2 == '万' || $p2 == '元'))) {

  $c = $p1 . $p2 . $c;

 } else {

  $c = $p1 . $c;

 }

 $i = $i + 1;

 $num = $num / 10;

 $num = (int)$num;

 if ($num == 0) {

  break;

 }

}

$j = 0;

$slen = strlen($c);

while ($j < $slen) {

 $m = substr($c, $j, 6);

 if ($m == '零元' || $m == '零万' || $m == '零亿' || $m == '零零') {

  $left = substr($c, 0, $j);

  $right = substr($c, $j + 3);

  $c = $left . $right;

  $j = $j-3;

  $slen = $slen-3;

 }

 $j = $j + 3;

}

if (substr($c, strlen($c)-3, 3) == '零') {

 $c = substr($c, 0, strlen($c)-3);

} // if there is a '0' on the end , chop it out

return $c . "整";

}

/**

* 特殊的字符

* @param [type] $str [description]

* @return [type]  [description]

*/

function makeSemiangle($str) {

$arr = array(

 '０' => '0', '１' => '1', '２' => '2', '３' => '3', '４' => '4',

 '５' => '5', '６' => '6', '７' => '7', '８' => '8', '９' => '9',

 'Ａ' => 'A', 'Ｂ' => 'B', 'Ｃ' => 'C', 'Ｄ' => 'D', 'Ｅ' => 'E',

 'Ｆ' => 'F', 'Ｇ' => 'G', 'Ｈ' => 'H', 'Ｉ' => 'I', 'Ｊ' => 'J',

 'Ｋ' => 'K', 'Ｌ' => 'L', 'Ｍ' => 'M', 'Ｎ' => 'N', 'Ｏ' => 'O',

 'Ｐ' => 'P', 'Ｑ' => 'Q', 'Ｒ' => 'R', 'Ｓ' => 'S', 'Ｔ' => 'T',

 'Ｕ' => 'U', 'Ｖ' => 'V', 'Ｗ' => 'W', 'Ｘ' => 'X', 'Ｙ' => 'Y',

 'Ｚ' => 'Z', 'ａ' => 'a', 'ｂ' => 'b', 'ｃ' => 'c', 'ｄ' => 'd',

 'ｅ' => 'e', 'ｆ' => 'f', 'ｇ' => 'g', 'ｈ' => 'h', 'ｉ' => 'i',

 'ｊ' => 'j', 'ｋ' => 'k', 'ｌ' => 'l', 'ｍ' => 'm', 'ｎ' => 'n',

 'ｏ' => 'o', 'ｐ' => 'p', 'ｑ' => 'q', 'ｒ' => 'r', 'ｓ' => 's',

 'ｔ' => 't', 'ｕ' => 'u', 'ｖ' => 'v', 'ｗ' => 'w', 'ｘ' => 'x',

 'ｙ' => 'y', 'ｚ' => 'z',

 '（' => '(', '）' => ')', '〔' => '[', '〕' => ']', '【' => '[',

 '】' => ']', '〖' => '[', '〗' => ']', '｛' => '{', '｝' => '}', '《' => '<',

 '》' => '>',

 '％' => '%', '＋' => '+', '—' => '-', '－' => '-', '～' => '-',

 '：' => ':', '。' => '.', '、' => ',', '，' => '.', '、' => '.',

 '；' => ';', '？' => '?', '！' => '!', '…' => '-', '‖' => '|',

 '”' => '"', '“' => '"', ''' => '`', '‘' => '`', '｜' => '|', '〃' => '"',

 '　' => ' ','．' => '.');

return strtr($str, $arr);

}

/**

* 下载

* @param [type] $filename [description]

* @param string $dir  [description]

* @return [type]   [description]

*/

function downloads($filename,$dir='./'){

$filepath = $dir.$filename;

if (!file_exists($filepath)){

 header("Content-type: text/html; charset=utf-8");

 echo "File not found!";

 exit;

} else {

 $file = fopen($filepath,"r");

 Header("Content-type: application/octet-stream");

 Header("Accept-Ranges: bytes");

 Header("Accept-Length: ".filesize($filepath));

 Header("Content-Disposition: attachment; filename=".$filename);

 echo fread($file, filesize($filepath));

 fclose($file);

}

}

/**

* 创建一个目录树

* @param [type] $dir [description]

* @param integer $mode [description]

* @return [type]  [description]

*/

function mkdirs($dir, $mode = 0777) {

if (!is_dir($dir)) {

 mkdirs(dirname($dir), $mode);

 return mkdir($dir, $mode);

}

return true;

}