It is particularly important to respond gracefully to interrupt signals such as Ctrl+C triggered SIGINT when developing PHP scripts that require long-running or listening, such as daemons or task queue workers. This article will explain how to use pcntl_signal with time_nanosleep to gracefully handle interrupt signals, allowing your script to exit safely, free up resources, and avoid data loss or abnormal states.

1. PDOStatement::columnCount() Introduction The columnCount() method is used to obtain the number of columns in the result set. It returns an integer indicating how many columns the query results contain.

In PHP development, it is very common to use the mysqli extension for database operations. The mysqli_result::fetch_column function is a simple method for extracting single column data from query results, but in actual use, many developers will encounter the problem of data duplication. This article will analyze the causes of duplicate data in response to this phenomenon and provide effective solutions and sample code to help everyone avoid this problem.

When interacting with a database using PDO (PHP Data Objects), the PDOStatement::rowCount function is often used to get the number of rows affected by the previous SQL statement. However, in some cases, the rowCount function may return a negative value. This article will analyze the common causes of this problem and provide corresponding solutions.

hexdec() is a very practical function, its main function is to convert hex strings into decimal integers. This function is often used to deal with scenes involving hexadecimal representations such as color code, network data, encrypted hash values.

In PHP image processing function, imagecreate and imagewbmp are two common functions, which are used to create image resources and output images into WBMP format respectively. The WBMP (Wireless Bitmap) format is a black and white image format for wireless devices. Although the usage scenarios are gradually decreasing, it is still useful in some lightweight systems or scenarios that are compatible with old devices. This article will introduce in detail how to use these two functions efficiently to generate images that suit your needs.

parse_url is a very practical function that parses the URL and extracts various parts of it, such as scheme, host, path, etc. However, in the requirement of obtaining subdomain names, parse_url does not directly provide the "subdomain name" field, so we must achieve the goal with the help of further parsing of host. However, there are some pits and details that are easily overlooked in this process, so we will discuss them in detail below.

In PHP's FTP function library, ftp_site() is a function that is rarely used by beginners but is very powerful. It allows developers to send SITE commands to the FTP server, thus performing some advanced operations supported by the server. This article will explain in detail the basic usage and operation steps of ftp_site(), helping you quickly master it and flexibly use it in FTP projects.

In PHP, the imagecreatefromxpm() function is used to create an image resource from an image file in XPM format. XPM format is a text-based image format, usually used for small icons or interface elements in UNIX/Linux environments. Although PHP's GD library supports loading XPM images through imagecreatefromxpm(), developers often need to save the loaded images into other formats, such as the commonly used PNG format.

Performance optimization of network communication is crucial when developing real-time systems. Especially in scenarios involving high concurrency and large data volume, reasonable buffer management and message delivery control will directly affect the overall performance of the system. This article will discuss how to efficiently control the message buffer through the socket_cmsg_space function and optimize the performance of the real-time system.

In modern web development, data integrity verification is a very important task. We need to ensure that during data transmission or storage, the data is not tampered with or corrupted. PHP provides a variety of hash-related functions to help developers achieve this requirement, among which hash_final() is one of the core functions used for hash context processing. This article will analyze in detail the purpose, how hash_final() works, and how to use it in actual projects for data integrity verification.

In web development, the processing of user authentication information usually involves frequent database queries or other more complex calculations, which undoubtedly increases the burden on the system. PHP's APCu extension provides an efficient caching mechanism that can be used to store user authentication information, thereby reducing the number of database queries and improving application performance. In this article, we will explore how to use the apcu_entry function to efficiently cache user authentication information.

In PHP development, when operating a database, you often need to obtain field information, such as field name, type, length, etc. This is especially common in scenarios such as generating dynamic tables and exporting data. mysql_fetch_field and mysqli_fetch_field are two functions used to obtain field definition information. They have certain functional similarities, but due to the evolution of PHP, there are obvious differences. This article will analyze their differences, functions and usage in detail.

time_nanosleep is a function used for high-precision delay, and its function signature is as follows:

1. What is array_slice? array_slice is a built-in array function in PHP, used to extract a sub-array from an array, similar to intercepting some elements in an array. The function signature is as follows:

The gmdate() function is used to format a date and time string based on Greenwich Standard Time (GMT). Unlike the date() function, gmdate() returns GMT time, not server local time. It is perfect for handling date-time requirements across time zones.

1. Introduction to the working principle of output_add_rewrite_var output_add_rewrite_var is a built-in function in PHP, which is used to automatically append a specified query variable and its value to all output URLs. Common usages are as follows:

User authentication is the basic link in building secure applications. When comparing passwords or tokens, unsafe string comparison methods may lead to a time attack, allowing the attacker to infer sensitive information. PHP provides a function hash_equals() specifically designed to prevent such attacks, which can compare two strings in a constant time manner to ensure security.

When using PHP to handle file system operations, control of permissions and ownership is one of the tasks that developers often encounter. PHP provides a series of functions to manipulate the owner information of a file or directory, where lchown() is a function used to modify the owner of a symbolic link. This article will quickly take you through the basic syntax, usage methods and some things to note about lchown().