Detailed explanation of PHP magic function application_PHP tutorial

PHP provides two magic reference functions magic_quotes_gpc and magic_quotes_runtime that are convenient for us to quote data. If these two functions are set to ON in php.ini, they will encounter single quotes ' and ' for the data we quote. Double quotation marks" and backslashes are automatically added to help us automatically translate symbols and ensure the correct operation of data operations. However, under different versions of PHP or different server configurations, some magic_quotes_gpc and magic_quotes_runtime are set to on. , and some are off, so the program we write must comply with both on and off conditions. So what is the difference between the two functions magic_quotes_gpc and magic_quotes_runtime? See the following description:

magic_quotes_gpc

The scope is: WＥＢclient server;
Action time: the request starts, for example, when the script is running.

magic_quotes_runtime

Scope of action: Data read from a file or the result of executing exec() or obtained from a SQL query;
Time of action: Every time the script accesses data generated in the running state.

So the setting value of magic_quotes_gpc will affect the data obtained through Get/Post/Cookies; the setting value of magic_quotes_runtime will affect the data read from the file or the data obtained from the database query

Example. Note:

＜form action="" method="post" ＞STR:＜input type="text" name="str"＞＜input type="submit"＞＜/form＞＜?php/* 我们在表单里填写:    '"    这些符号,如果magic_quotes_gpc没有开启，那么他们不会被反斜杠转义 */echo '现在通过POST传递过来的值是：' ,$_POST['str'], '＜br /＞';if (get_magic_quotes_gpc()) {      // 检查magic_quotes_gpc是否打开,如果没有打开，用addslashes进行转义      $str = $_POST['str'];} else {      $str = addslashes($_POST['str']);}echo '这里是转义过后的:' ,$str, '＜hr /＞';$sql = "INSERT INTO lastnames (lastname) VALUES ('$str')";//=====================================================================================//-----magic_quotes_gpc只会转义：     通过Get/Post/Cookies获得的数据//-----magic_quotes_runtime会转义：从文件中读取的数据或执行exec()的结果或是从ＳＱＬ查询中得到的//=====================================================================================$data = implode(file('try.php'));      // 我们在里面依然写'"这几个字符，用来测试echo '这里是try.php的数据,';if (get_magic_quotes_runtime()) {      $data = $data;      echo '被系统自带转义的' .$data;} else {      echo '被addslashes转义了的' .$data = addslashes($data);}$sql = "INSERT INTO lastnames (lastname) VALUES ('$data')";echo '＜br /＞SQL语句为：＜br /＞' ,$sql;//---入库都转义了，但是多余了反斜杠，我们要读出来是原来的数据时候使用stripslashes()去掉反斜杠//---stripslashes()和addslashes()作用相反?＞

The most critical difference is the two points mentioned above: they target different processing objects
The setting value of magic_quotes_gpc will affect the use of Get/Post/Cookies Obtained data
The setting value of magic_quotes_runtime will affect the data read from the file or the data obtained from the database query

By the way, here are a few functions that I want to associate:

set_magic_quotes_runtime():
Set the magic_quotes_runtime value. 0=off. 1=on. The default state is off. You can view magic_quotes_runtime through echo phpinfo();

get_magic_quotes_gpc():
magic_quotes_gpc value.0=off.1=on.

get_magic_quotes_runtime():
View magic_quotes_runtime value. 0=off. 1=on.

Note that there is no set_magic_quotes_gpc() function, that is, the value of magic_quotes_gpc cannot be set in the program.