When making HTTP requests with PHP, curl is one of the most commonly used libraries. It allows us to perform various tasks, such as sending GET or POST requests. To optimize performance, sometimes we want to reuse an established connection to avoid the overhead of establishing a new connection every time. This brings us to the concept of HTTP persistent connections.

First, we need a simple PHP socket service script that listens on a certain port, accepts connections, and responds simply.

Handling compressed files in PHP is a common task, especially when dealing with uploaded archive data or automated deployments. Among the available methods, zip_read() is an older interface of ZipArchive that allows you to step through each entry within a ZIP file. Although this method has largely been replaced by the object-oriented ZipArchive class, zip_read() still has practical value for certain projects or compatibility requirements.

In PHP, the passthru() function is used to execute external system commands and pass their output directly to the browser. This function is widely used, especially when performing system-level operations such as software installation or system updates, offering powerful functionality. This article explains how to use the passthru() function to execute software installation or system update commands, along with some important tips and precautions.

When developing PHP applications, page redirects are a common operation. Typically, developers use the header() function to perform the redirection. However, if the page outputs any content, such as HTML tags or error messages, before performing the redirection, it may cause the redirection to fail or result in unexpected behavior. To ensure the redirect is successful and prevent unnecessary output from interfering, using the ob_clean() function becomes crucial.

In PHP programming, ob_clean() is a common output buffer management function. It clears the current output buffer without sending its contents. Many developers encounter issues where the cache doesn't clear after calling ob_clean(), causing confusion as to why the buffer still retains content despite the function call.

In PHP development, the ob_clean() function is used to clear the output buffer, which is common during debugging and performance tuning. However, in some situations, you may encounter the following error message:

This article discusses the nuances of using ob_clean() followed by ob_flush() in PHP output buffering. It explains how these functions work individually and together, highlighting key points and precautions for their proper use in managing output buffering effectively.

When working with images in PHP, the imagecolorstotal() function is a common tool used to get the total number of colors in an image resource. When encountering errors with imagecolorstotal(), many developers first suspect issues with the image file path, file existence, or proper loading. However, sometimes the problem lies elsewhere. This article will guide you through troubleshooting and resolving these issues to ensure your code runs smoothly.

When working with databases in PHP, PDO (PHP Data Objects) serves as a powerful and secure abstraction layer. The PDOStatement::fetch() method is a common way to retrieve a single record from a query result. This article provides a detailed guide on how to efficiently use the fetch() function to get a single result, including step-by-step instructions and sample code to help you get started quickly and avoid common pitfalls.

This article explains how to implement error correction and feedback features in an online quiz system, providing code examples to help learners optimize their quiz experience and improve learning outcomes.

In PHP development, there are times when we need to temporarily set environment variables for the current script to pass configuration information or influence program behavior during runtime. PHP provides the putenv() function to accomplish this. This article explains how to use putenv(), its applicable scenarios, and important considerations when using it.

PHP's closelog() is idempotent, meaning it won't cause errors if called multiple times. However, this could mask issues in the program where resources are being cleaned up repeatedly. For example, if a function is called multiple times but closelog() is executed each time, it may indicate unclear resource management logic.

In high concurrency scenarios, managing database transactions is particularly important. When using PHP's PDO extension, making proper use of PDO::inTransaction() can help you efficiently manage transactions and avoid errors.

When using the MySQLi extension, mysqli::stmt_init is the standard way to create a statement object, while the prepare function is used to prepare SQL queries. Many developers may encounter situations where the prepare function is called repeatedly within loops or multiple queries. However, does repeatedly calling the prepare function impact performance? This article will analyze the issue through practical testing and offer optimization suggestions.

Learn how to dynamically set the namespace URI using variables in PHP's registerXPathNamespace function. This guide covers basic usage, dynamic URI generation from configuration files, and more.