


PHP user login code (limiting the number of incorrect user logins) (1/2)_PHP tutorial
PHP user login code (limit the number of incorrect user logins)
php tutorial user login code (limit the number of incorrect user logins)
/* User login operation */session_start();
include("mysql tutorial.class. php");
$db=new mysql('localhost', 'root', '', 'flx', 'conn', 'gbk');
// For the convenience of testing, here is just a simple definition A specific user is identified. In actual operation, the user information is derived from the database tutorial;
define('user','admin');
define('pw', 123);
$ db->findall('limit_login');
$row=$db->fetch_array();
//print_r($row);
if($_post['submit']) {
$username=$_post["username"];
$pw=$_post["pw"];
$_session['time']=time();
/* Error Judgment of times exceeding the limit*/
// For users who have logged in more than three times, if the current time, minus the time when the login started, is less than a specific value,
will not be allowed to log in;
if ($username==user){
//Here the user can try to log in 3 times. The following is written as 2 because the page refresh is not synchronized with the database connection.
//That is to say, the second time When the error message is inserted into the database, the information obtained here is still the first time. The number of actual user errors has been increased once;
if($row['login_times']>2){
$current=time();
$passed_time=$current-$row['login_date'];
echo 'Now has passed'.$passed_time.' seconds
';
// Set the time to 900 seconds. During this time period, specific users cannot log in to the system; press
if(($current-$row['login_date']) //$test_pw =substr(md5(rand()),0,10);
//Now the admin (specific user) user has logged in incorrectly more than 3 times, then within the limited time,
//Even if his password Even if the input is correct, you cannot log in to the system;
if($pw==pw){
exit('You entered the wrong password more than three times, please log in to the system after 15 minutes!');
}
// Of course, the password entered by this user is not the correct password, and such a prompt is given;
if($pw!=pw){
exit('You entered the wrong password more than three times , please log in to the system after 15 minutes!');
}
}else{
} //The time limit has passed and this user can log in. Before this user logs in, To clear the last login time
;
$mod_content="`login_times`=0,`login_date`=0";
$condition="`id`=1";
$db->update('limit_login',$mod_content,$condition);
}
}
}
if($username&&$pw){
if($username==user&&$pw==pw){
/* User login is successful, */
// Update data table; table login The times and time are both set to zero;
$mod_content="`login_times`=0,`login_date`=0";
$condition="`id`=1";
$db-> update('limit_login',$mod_content,$condition);
echo '';
}else{
} //When the first error occurs, set the number of password errors to 1, and put the time when the session is saved during login into the database;
if ($row['login_times']==0&&$row['login_date']==0){
$mod_content="`login_times`=1,`login_date`='".$_session['time'] ."'";
$condition="`id`=1";
$db->update('limit_login',$mod_content,$condition);
}else{
$ mod_content="`login_times`=`login_times`+1";
$condition="`id`=1";
$db->update('limit_login',$mod_content,$condition);
} /*Reminder that there are still several opportunities for users*/
if ($ row ['login_times'] & lt; 3) {
$ row ['login_times'] ++; // Here The reason for adding 1 to the number of logins is the same as the reason mentioned above, which is due to the inability to synchronize the connection to the
database;
echo 'Wrong password! The number of errors is: '.$row['login_times'].' times< ;br> '; }else{
echo 'Username and password cannot be empty! ';
}
}
?> > username:
password:
1 2
http://www.bkjia.com/PHPjc/444885.html
www.bkjia.com
true

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


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