//几个有效的$_SERVER信息
$_SERVER['HTTP_USER_AGENT']; //内核信息
$_SERVER['HTTP_REFERER']; //来源信息
$_SERVER['SERVER_ADDR']; //服务端IP
$_SERVER['REMOTE_ADDR']; //客户端IP
$str = "https://www.baidu.com/";
if(strpos($str,'http') !== false){
echo "存在";
}else{
echo "不存在";
}
//判断是否为微信浏览器
function is_weixin(){
if(strpos($_SERVER['HTTP_USER_AGENT'], 'MicroMessenger') !== false){
return true;
}
return false;
}
//来源不是本站点,返回第一步
if(strpos($_SERVER['HTTP_REFERER'], WEB_URL)===false) {
header('Location:/');
}
//判断访问设备是iso还是android系统
if(strpos($_SERVER['HTTP_USER_AGENT'], 'iPhone')||strpos($_SERVER['HTTP_USER_AGENT'], 'iPad')){
echo 'systerm is IOS';
}else if(strpos($_SERVER['HTTP_USER_AGENT'], 'Android')){
echo 'systerm is Android';
}
//手机号码中间隐藏
$mobile = '18812345678';
echo preg_replace('/(\d{3})(\d{4})/',"$1****", $mobile);
//字符串拼接
$cost_point = 108;
$scale = 48.6;
$desc = sprintf('我已上够%s节课,超过了全国%s的用户,你也快来挑战上课记录吧!', $cost_point, $scale . '%');
/**
* str_replace函数详解
* str_replace($search , $replace , $subject [, int &$count ] )
* 参数说明:$search要被搜索替换的字符串,$replace要替换搜索的字符串,$subject操作的字符串,&$count替换次数
* $search和$replace都为数组
* 示例:str_replace(array("a", "p"), array("apple", "pear"), "I like eat apple.");
* 说明:在$subject中将$search的各元素值依次分别替换为$replace的各元素值。
* 返回:"I like eapearpearlet apearpearlepearpearle."
*/
$str = str_replace(array("a", "p"), array("apple", "pear"), "I like eat apple.");
//var_dump($str);die; //I like eapearpearlet apearpearlepearpearle.
//文件读取
$str = file_get_contents("filename.txt");
$newStr = str_replace(array("\n","\r",',,'),array(',', ',', ','),$str);
//文件写入
file_put_contents ('./filename.txt', "1222\n",FILE_APPEND); //追加写入
file_put_contents ('./filename.txt', "1222\n"); //替换写入