非常实用的PHP常用函数汇总

本文实例总结了一些在php应用开发中常用到的函数，这些函数有字符操作，文件操作及其它的一些操作了，分享给大家供大家参考。具体如下：

<?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;}