In PHP, using MySQL databases for data manipulation is a very common requirement. The mysqli extension provides two ways to use process-oriented and object-oriented. The most basic operation is to establish a database connection through the connect() function, and then execute SQL statements using the mysqli_query() function. This article will introduce how to implement database connections and operations with mysqli_connect() and mysqli_query() functions.

When using PHP for Socket-based programming, socket_accept() is a key function that accepts connections from clients. However, if the function call fails, an error may be thrown, causing the program to break or unpredictable behavior. Therefore, catching these errors and recording them in the log is very necessary for debugging and operation and maintenance.

Performance optimization is an aspect that developers are very concerned about when using cURL for network requests in PHP. cURL itself supports Connection Reuse, which can reduce the overhead caused by frequent TCP connection establishment. In order to further improve the efficiency in multi-request scenarios, PHP cURL provides the curl_share_init() function, which is used to share some resources between multiple cURL handles, such as DNS cache, connection handles, etc. So, is curl_share_init() suitable for long connection multiplexing? What role can it play in long connection management? This article will be based on the actual situation

When PHP uses cURL to perform multiple HTTP requests, sometimes we want to share certain data between multiple requests, such as cookies, DNS caches, or SSL sessions. At this time, you can use curl_share_init() and related functions to implement sharing. However, many developers encounter a common problem when trying to use the feature: This article will analyze the causes and solutions of this problem in detail.

The crypt() function is a commonly used encryption function, mainly used to encrypt strings in one-way, especially when dealing with password storage. This article will parse the parameters of the crypt() function in detail and demonstrate through examples how to safely encrypt strings with PHP's crypt() function.

In modern PHP application development, the ORM (Object Relational Mapping) framework has become the mainstream way to connect applications and databases. Frameworks such as Laravel's Eloquent, Doctrine, and RedBeanPHP have greatly simplified the complexity of database operations. However, the convenience of ORM is often accompanied by performance sacrifice, especially in high concurrency or large data volume scenarios, bottlenecks in underlying database connection and query performance gradually emerge.

In web development, user input is the most common and most easily attacked entry. To improve the security of user input processing, PHP provides many practical functions, among which filter_input() and crypt() are two very important security tools. This article will introduce how to use these two functions in combination to effectively prevent common attack methods such as XSS (cross-site scripting attack) and password leakage.

We can use the imagecolorallocatealpha function and the imagesavealpha function to set the transparent channel of the image, so that the image supports a transparent background. This is very useful for retaining transparency when generating PNG images, moving image processing, or image editing. This article will explain in detail how to use these two functions to handle transparent images.

In PHP development, frequent call to the RESTful interface is a very common scenario, especially in microservice architectures, communication between different services often depends on HTTP requests. cURL is the most commonly used extension in PHP to handle HTTP requests. Although the performance overhead of a single request is usually acceptable, in high concurrency scenarios, if each request repeatedly initializes the connection resource, it will cause a considerable performance bottleneck.

When drawing images in PHP, we often need to draw straight lines, such as in image processing scenarios such as generating charts, graphics or watermarks. However, lines drawn by default may have jagged edges that don't look smooth enough. At this time, we can use the imageantialias() function to combine imageline() to achieve a smoother and more natural line effect.

mysqli_stmt::attr_set and mysqli_stmt::attr_get are methods used to set and get the properties of mysqli_stmt (preprocessing statements). Although these two methods are not often used frequently in actual development, they show strong flexibility in adjusting the behavior of statements in specific scenarios. This article will demonstrate how to set and get property values ​​using these two functions through a complete process.

The get_defined_constants function returns an array containing all defined constants and their corresponding values. Const is defined by the define() or const keyword, and they are unchangeable throughout the script.

Frequent initialization and release of cURL resources can cause performance waste when making high concurrent HTTP requests in PHP, especially when it involves a large number of concurrent connections. To solve this problem, the curl_share_init function provides a way to share specific resources, such as DNS cache, cookies, etc., thereby improving execution efficiency in multi-threaded or multi-process environments.

In daily system management or development processes, we sometimes need a simple user verification mechanism, especially when building command line tools. Although we prefer to use OAuth, JWT or database authentication mechanisms in production environments, in some lightweight scenarios, a user authentication tool based on the crypt() function is sufficient.

When using PHP's crypt() function for password hashing, the security of salt directly affects the security of password storage. The function of salt value is to prevent the same password from generating the same hash value, thereby effectively resisting rainbow table attacks. Therefore, it is very important to generate a safe and reliable salt value.

When making efficient network requests in PHP, we often need to use cURL to initiate HTTP requests. However, when certain resources (such as cookies, file descriptors, etc.) need to be shared among multiple cURL requests, traditional cURL requests may experience resource competition and synchronization issues. To solve this problem, PHP provides the curl_share_init function, which helps us share resources between multiple cURL handles. This article will explore in-depth how to use curl_share_init to achieve shared resource synchronization in multiple PHP subprocesses.

The mysqli_stmt::attr_get function is a relatively unpopular but very useful function when using PHP's MySQLi extension for database operations. It can be used to obtain the attribute value of a preprocessing statement object, thereby helping us determine whether a property constant is supported by the current MySQL server and client. This article will introduce in detail how to use the mysqli_stmt::attr_get function to judge the support of attribute constants and give example code.

When building a user authentication system, safe handling of passwords is an issue that developers must pay attention to. Comparing passwords incorrectly may cause the system to be subject to security threats such as Timing Attacks. PHP provides some built-in functions that can help us handle password verification securely. Among them, the combination of crypt() and hash_equals() is a relatively safe way of practice.

In PHP, the crypt() function is a traditional method for encrypting passwords. It supports multiple encryption algorithms and enables specific encryption mechanisms by passing in salt values ​​in different formats. Although more modern password hashing APIs (such as password_hash()) have been recommended in recent years, crypt() is still widely used in some old systems. Therefore, understanding how to choose the appropriate algorithm and salt value format for the crypt() function is the key to ensuring security and system compatibility.

In PHP's GD library, the imagecolorallocatealpha() function is often used to create color resources with transparency. In image processing, this function is often called to assign colors to the image, especially when the image has a transparent background or needs to process an alpha channel. However, in practical applications, many people will encounter a problem: multiple calls to imagecolorallocatealpha() to allocate colors will cause color resource overflow. The root of this problem lies in the relationship between resource management and PHP memory limitations.