10个必看的PHP小代码，很实用！

获取浏览器IP地址

　　function getRemoteIPAddress() {

　　$ip = $_SERVER['REMOTE_ADDR'];

　　return $ip;

　　}

　　如果有代理服务器的情况下获取IP

　　function getRealIPAddress() {

　　if (!empty($_SERVER['HTTP_CLIENT_IP'])) { // check ip from share internet

　　$ip = $_SERVER['HTTP_CLIENT_IP'];

　　} elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) { // to check ip is pass from proxy

　　$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];

　　} else {

　　$ip = $_SERVER['REMOTE_ADDR'];

　　}

　　return $ip;

　　}

　　获取 MySQL 时间戳

　　$query = "select UNIX_TIMESTAMP(date_field) as mydate from mytable where 1=1";

　　$records = mysql_query($query) or die(mysql_error());

　　while($row = mysql_fetch_array($records)) {

　　echo $row;

　　}

　　验证日期格式：YYYY-MM-DD

　　function checkDateFormat($date) {

　　// match the format of the date

　　if (preg_match("/^([0-9]{4})-([0-9]{2})-([0-9]{2})$/", $date, $parts)) {

　　// check whether the date is valid of not

　　if (checkdate($parts[2], $parts[3], $parts[1])) {

　　return true;

　　} else {

　　return false;

　　}

　　} else {

　　return false;

　　}

　　}

　　重定向

　　header('Location: http://www.phpchina.com');

　　发送邮件

　　$to = "someone@oschina.net";

　　$subject = "Your Subject here";

　　$body = "Body of your message here you can use HTML too. e.g.

Bold ";

　　$headers = "From: You\r\n";

　　$headers .= "Reply-To: info@yoursite.com\r\n";

　　$headers .= "Return-Path: info@yoursite.com\r\n";

　　$headers .= "X-Mailer: PHP\n";

　　$headers .= 'MIME-Version: 1.0' . "\n";

　　$headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";

　　mail($to, $subject, $body, $headers);

　　BASE64 编码和解码

　　function base64url_encode($plainText) {

　　$base64 = base64_encode($plainText);

　　$base64url = strtr($base64, '+/=', '-_,');

　　return $base64url;

　　}

　　function base64url_decode($plainText) {

　　$base64url = strtr($plainText, '-_,', '+/=');

　　$base64 = base64_decode($base64url);

　　return $base64;

　　}

　　JSON 处理

　　$json_data = array ('id'=>1,'name'=>"John",'country'=>'Canada',"work"=>array("Google","Oracle"));

　　echo json_encode($json_data);

　　$json_string='{"id":1,"name":"John","country":"Canada","work":["Google","Oracle"]} ';

　　$obj=json_decode($json_string);

　　// print the parsed data

　　echo $obj->name; //displays John

　　echo $obj->work[0]; //displays Google

　　检测用户浏览器类型

　　$useragent = $_SERVER ['HTTP_USER_AGENT'];

　　echo "Your User Agent is: " . $useragent;

　　显示网页源码

　　$lines = file('http://www.phpchina.com/index.php');

　　foreach ($lines as $line_num => $line) {

　　// loop thru each line and prepend line numbers

　　echo "Line #<b>{$line_num}</b> : " . htmlspecialchars($line) . "<br>\n";

　　}

　　调整服务器时间

　　$now = date('Y-m-d-G');

　　$now = strftime("%Y-%m-%d-%H", strtotime("$now -8 hours"));