WebSafe

1-2-5_PHP-1

PHP

脚本范围 <?php ?>

注释 // # /* */

输出

  • echo 输出多个
    －print为函数，有返回值
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$a = "Welcome to";
$b = "Study PHP";

// echo 可以用逗号分隔变量来显示
echo = "echo输出:".$a,$b."</br>";
// print 只能用点好.来分隔，不能用逗号，否则会报错
print = "print函数:".$a.$b."</br>";
echo 'echo 打印print返回1:'.print $a.$b.'<br />';

用PHP代码实现web常见功能

注册功能

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<form action="welcome.php" method="post">
name : <input type="text" name="name"><br>
email : <input type="text" name="email"><br>
<input type="submit">
</form>
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# welcome.php

<?php echo $_POST['name'];?> Welcome Come! <br />
Your email is <?php echo $_POST['email'];?>

Tip 除了 $_POST 和$_GET 还有$_REQUEST，可接收上面2者请求

$_FILES

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<form action="" method="post" enctype="multipart/form-data">
    <label for="file">Filename:</label>
    <input type="file" name="file" id="file" />
    <br />
    <input type="submit" name="submit"  value="submit" />
</form>

<?php

if (isset($_REQUEST["submit"])){

    if($_FILES["file"]["error"] > 0){
        echo "Return Code:".$_FILES["file"]["error"]."<br />";
    }else{
        echo "Upload:".$_FILES["file"]["name"]."<br />";
        echo "Type:".$_FILES["file"]["type"]."<br />";
        echo "Size:".($_FILES["file"]["size"] / 1024)."Kb<br />";
        echo "Temp File:".$_FILES["file"]["tmp_name"]."<br />";
    }
    if(!file_exists("uploads")){
        mkdir("uploads");
    }
    if( file_exists("uploads/".$_FILES["file"]["name"])){
        echo $_FILES["file"]["name"]."is aleady exists!" ;
    }else{
        move_uploaded_file($_FILES["file"]["tmp_name"]),
        "uploads/".$_FILES["file"]["name"]);
        echo "Store in"a."uploads/".$_FILES["file"]["name"];
    }
}

$_SERVER

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<?php
echo "服务器名称:".$_SERVER["SERVER_NAME"]."<br />";
echo "网站根目录:".$_SERVER["DOCUMENT_ROOT"]."<br />";
echo "当前网页相对路径:".$_SERVER["PHP_SELF"]."<br />";
echo "当前页面绝对路径:".$_SERVER["SCRIPT_FILENAME"]."<br />";
echo "当前服务器环境变量:".$_SERVER["PATH"]."<br />";
?>

其他变量

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$_GLOBALS
$_ENV
$_COOKIE
$_REQUEST
$_SESSION

包含文件

  • include “xxx.php” # 警告，脚本继续运行
  • require “xxx.php” # 错误，脚本停止