current location:Home > Technical Articles > System Tutorial > LINUX

  • Understand the session garbage collection mechanism in php
    Understand the session garbage collection mechanism in php
    1. The session generation mechanism in PHP. Let’s first analyze how a session is generated in PHP. The purpose of designing session is to maintain various states of each user to make up for the shortcomings of the HTTP protocol (stateless). We now have a question. We all know that session is saved on the server. Since it is used to maintain the status of each user, what does it use to distinguish users? At this time, you have to use cookies. When we call session_start(); in the code, PHP will generate a file each to the SESSION storage directory (default is /tmp/) and the client's cookie directory. session
    LINUX 332 2024-08-08 09:08:11
  • What process do you go through when entering a URL in your browser?
    What process do you go through when entering a URL in your browser?
    1: Description of related concepts: 1.1: DNS (DomainnameSystem) cache: (Domain name system) (check the ipconfig/displaydns of the local machine) After the computer resolves a domain name, it associates this domain name with the host IP address , the computer saves this relationship in the DNS cache table. The next time the computer enters www.baidu.com, the computer will know the IP address corresponding to this domain name by searching the DNS cache, and no longer perform domain name resolution, which improves Improved efficiency 1.2: IP address: The IP address corresponds to a house number. We can find the location of the host through this address. 1.3: Domain name: (domainname)
    LINUX 933 2024-08-08 08:16:02
  • Modify hosts file and hostname: easily realize domain name and IP address mapping
    Modify hosts file and hostname: easily realize domain name and IP address mapping
    Directory 1. Modify the hosts file. The hosts file is a configuration file under /etc. The LINUX delete directory records the IP address corresponding to the domain name or host name. Every computer on the Internet will have an IP address, which is similar to a specific door steel number. This machine can be accessed through the IP address. However, it is difficult to remember the IP address and modify it in the linuxhosts file, so you can use the method of mapping the IP address to the domain name to access the specific host by accessing the domain name. The hosts file records this mapping relationship. Change hosts: First, ping Baidu to get an ipvim/etc/hosts. Add the IP copied above to hosts where baidubaidu1 leads to the previous IP two.
    LINUX 1048 2024-08-08 01:54:33
  • What should I do if the Linux command line displays garbled characters? Set the character encoding to UTF-8 to solve the problem
    What should I do if the Linux command line displays garbled characters? Set the character encoding to UTF-8 to solve the problem
    When the Linux command line displays garbled characters, you can try setting the character encoding to UTF-8. It can be set through the following commands:,, "bash, exportLC_ALL=en_US.UTF-8, exportLANG=en_US.UTF-8," In Linux systems, it is a common problem for the command line to display garbled characters, which is generally due to character encoding. This article will introduce in detail how to solve the problem of garbled characters displayed on the Linux command line due to incorrect settings. 1. Understand character encoding. Before solving this problem, we need to understand the basic concept of character encoding. Character encoding is a correspondence between characters (such as letters, numbers, and punctuation marks) and two's complement numbers (0 and 1). relations advance
    LINUX 466 2024-08-08 01:37:43
  • Detailed steps and methods for modifying the hosts file in Android system
    Detailed steps and methods for modifying the hosts file in Android system
    For some reasons, it may be necessary to change the domain name specified in the hosts file to the corresponding IP address. Android is a Linux-based system. Similar to Linux, it is set up through the hosts file. Under Android, /etc is the Linux training link to /system/etc. We need to change /system/etc/hosts to achieve this. And this file is read-only and cannot be changed directly through the shell. This can be changed by connecting to a PC using adb. The steps are as follows: 1. Obtain root permissions: adbroot 2. Set /system to be readable and writable: adbremount 3. Copy the hosts file to PC: a
    LINUX 589 2024-08-07 22:43:44
  • Red Hat Linux system download, installation, system monitoring, and process management tutorials
    Red Hat Linux system download, installation, system monitoring, and process management tutorials
    Table of Contents of Series Articles Chapter 1: Redhat Linux System Download and Installation Chapter 2: Linux Users and Groups Chapter 3: Linux File Management Chapter 4: Linux Directory Management Chapter 5: Linux Text Editor Chapter 6: Linux File Search and Management Chapter 7: Linux input, output redirection and pipeline Chapter 8: Linux package management Chapter 9: Linux system monitoring and process management Article table of contents Preface The main content of this blog is about system monitoring and process management, etc. The operation is still based on experiments. Follow the old rules and remember to take a snapshot in advance. 1. System monitoring query information uname-runame-alscpuhostnametoptop command
    LINUX 666 2024-08-07 21:36:43
  • STM32 and Linux: From hardware to software, the key to mastering the operating system mechanism
    STM32 and Linux: From hardware to software, the key to mastering the operating system mechanism
    Hello, landlord! I'm not going to talk to you about the big ideas like those above, but I'm going to talk to you about the practical things. Linux and stm32 are a software platform and a hardware platform, which are completely different (remember, they are platforms!). Let's put it this way, since you like microcontrollers, you should first learn the detailed explanation of stm32 embedded Linux device driver development and lay a solid foundation for the hardware, especially various buses (usb, iic, spi...), various peripheral modules (infrared , Wenhu, mpu6050...), and then focused on ucosii, that is to say, learn to complete your tasks within the framework of the operating system, rather than simply writing programs - the understanding of the operating system mechanism Grasp is the key to distance yourself from the MCU friends around you;
    LINUX 563 2024-08-07 21:00:24
  • Centos6.4 Installation Guide: Detailed Graphical Tutorial on Installation via USB Disk
    Centos6.4 Installation Guide: Detailed Graphical Tutorial on Installation via USB Disk
    If you want to install Centos6.4, in fact, the first thing you will think of is using a USB flash drive as a carrier. Because the USB flash drive has a relatively high usage rate, is easy to carry and efficient in storage, it is one of the best choices. Tomorrow the editor will explain it to you. Provides detailed graphic and text strategies for installing Centos 6.4 via USB flash drive. 1. First we need to download UltraISO (floppy disk) and Centos6.4 image, install the software, insert the USB disk, open the UltraISO software, find the Centos6.4 installation image (as shown in the figure), delete other files and keep only images and isolinux Two folders and the TRANS.TBL file, only these three files are enough. 2. As shown in the figure, select "Write" under the "Start" button
    LINUX 568 2024-08-07 20:40:53
  • H2Miner virus invades Windows/Linux platform, beware of long-term persistence of mining programs
    H2Miner virus invades Windows/Linux platform, beware of long-term persistence of mining programs
    H2Miner alertness level★★★Affected platforms: Windows/Linux virus execution body Description Attackers use vulnerabilities to invade Windows platforms and Linux platforms. On the Windows platform, the attacking host downloads and executes the XML file wbw.xml, executes a PowerShell command in the XML file, and downloads a script named 1.ps1. This script downloads the mining program and mining configuration file and renames it for execution. , create a scheduled task and execute the 1.ps1 script every 30 minutes to achieve persistence and stay on the attack host all year round; on the Linux platform, the attack host downloads and executes an XML file named wb.xml, which is embedded using the same method. Got it
    LINUX 909 2024-08-07 20:40:30
  • Introduction to popular Linux systems and methods of making USB boot images
    Introduction to popular Linux systems and methods of making USB boot images
    This article mainly introduces several popular Linux systems. Basically, Debian and Ubuntu systems are similar. First, suselinux. What should be noted here is that you must have a Linux or FreeBSD system on hand to use the zcat command. In fact, it must also be a system that can recognize USBStorage. Usually, you can use VMWare to serve any minimal Linux. Then go to the corresponding Linux release version to download a bootable img to the U disk. The download address is as follows: DebianSid:/debian/dists/sid/ma...dia/boot.img.gz (This is to make the U disk boot
    LINUX 996 2024-08-07 19:48:21
  • Microservice architecture—graceful shutdown solution
    Microservice architecture—graceful shutdown solution
    Abstract: Application graceful shutdown in microservice architecture mainly refers to the planned and smooth exit of application instances (that is, no incidents that need to be handled). 1 Introduction Graceful downtime of applications in microservice architecture mainly refers to the planned and smooth exit of application instances (that is, without causing incidents that need to be handled). Application server shutdowns are mainly divided into two categories: active shutdowns and passive shutdowns, of which active shutdowns and most passive shutdowns can achieve graceful shutdowns. If the application does not shut down gracefully, the following situations will occur: Data loss: The data in the memory has not been persisted to the disk. File corruption: The file being written is not updated due to file corruption. Request loss: Queued for processing. Request lost and response lost: the successful transaction has not had time to respond to the transaction
    LINUX 679 2024-08-07 18:47:02
  • How to put a website into memory to speed up the website under Linux
    How to put a website into memory to speed up the website under Linux
    /dev/shm/ is a device file, which uses the tmpfs file system (note: under Centos and Redhat, the /dev/shm directory is a link pointing to the /run/shm directory, which corresponds to the tmpfs file system under the Ubuntu system It is the /run/shm directory (you can use the df command to view it), because the /dev/shm/ directory is not on the hard disk, but in the memory. It is the so-called tmpfs. You can view it through the command df-h. The default size of tmpfs is half of the physical memory. Of course, it can be adjusted according to the actual situation. First create a directory wpcachemkdir/dev for WordPress’s cache files.
    LINUX 1108 2024-08-07 18:46:33
  • How to install and configure ArangoDB
    How to install and configure ArangoDB
    ArangoDB is an open source distributed native multi-model database. It is a NoSQL database with three data models: graph, document and key/value. ArangoDB uses SQL-like query language (AQL) to build high-performance applications. ArangoDB installation ArangoDB supports installation on Windows, Linux, Docker, Mac and other systems. Installation of ArangoDB under Windows You can download the compressed package version or the executable file version under Windows. I prefer to use the compressed package version. After downloading, just select a directory and decompress it directly. untie
    LINUX 698 2024-08-07 18:19:21
  • Linux uses instructions to release cache methods
    Linux uses instructions to release cache methods
    The caching mechanism of the Linux system is quite advanced. It caches dentry (used for VFS to accelerate the conversion of file path names to inodes), BufferCache (for reading and writing disk blocks) and PageCache (for reading and writing file inodes). operate. However, after a large number of file operations are performed, the cache will basically use up the memory resources. But in fact, our file operation has been completed, and this part of the cache is no longer used. At this time, can we just watch the cache occupy the memory space? Therefore, we still need to manually release the memory under Linux, which is actually the operation of releasing the cache. To achieve the purpose of releasing the cache, we first need to
    LINUX 968 2024-08-07 16:33:47
  • How to connect two Ubuntu hosts to the Internet using one network cable
    How to connect two Ubuntu hosts to the Internet using one network cable
    How to use one network cable to connect two ubuntu hosts to the Internet 1. Prepare host A: ubuntu16.04 and host B: ubuntu16.042. Host A has two network cards, one is connected to the external network and the other is connected to host B. Use the iwconfig command to view all network cards on the host. As shown above, the network cards on the author's A host (laptop) are: wlp2s0: This is a wireless network card. enp1s0: Wired network card, the network card connected to host B. The rest has nothing to do with us, no need to care. 3. Configure the static IP of A. Edit the file #vim/etc/network/interfaces to configure a static IP address for interface enp1s0, as shown below (where #==========
    LINUX 338 2024-08-07 13:39:22

Tool Recommendations

jQuery enterprise message form contact code

jQuery enterprise message form contact code is a simple and practical enterprise message form and contact us introduction page code.
form button
2024-02-29

HTML5 MP3 music box playback effects

HTML5 MP3 music box playback special effect is an mp3 music player based on HTML5 css3 to create cute music box emoticons and click the switch button.

HTML5 cool particle animation navigation menu special effects

HTML5 cool particle animation navigation menu special effect is a special effect that changes color when the navigation menu is hovered by the mouse.
Menu navigation
2024-02-29

jQuery visual form drag and drop editing code

jQuery visual form drag and drop editing code is a visual form based on jQuery and bootstrap framework.
form button
2024-02-29

Organic fruit and vegetable supplier web template Bootstrap5

An organic fruit and vegetable supplier web template-Bootstrap5
Bootstrap template
2023-02-03

Bootstrap3 multifunctional data information background management responsive web page template-Novus

Bootstrap3 multifunctional data information background management responsive web page template-Novus
backend template
2023-02-02

Real estate resource service platform web page template Bootstrap5

Real estate resource service platform web page template Bootstrap5
Bootstrap template
2023-02-02

Simple resume information web template Bootstrap4

Simple resume information web template Bootstrap4
Bootstrap template
2023-02-02

Cute summer elements vector material (EPS PNG)

This is a cute summer element vector material, including the sun, sun hat, coconut tree, bikini, airplane, watermelon, ice cream, ice cream, cold drink, swimming ring, flip-flops, pineapple, conch, shell, starfish, crab, Lemons, sunscreen, sunglasses, etc., the materials are provided in EPS and PNG formats, including JPG previews.
PNG material
2024-05-09

Four red 2023 graduation badges vector material (AI EPS PNG)

This is a red 2023 graduation badge vector material, four in total, available in AI, EPS and PNG formats, including JPG preview.
PNG material
2024-02-29

Singing bird and cart filled with flowers design spring banner vector material (AI EPS)

This is a spring banner vector material designed with singing birds and a cart full of flowers. It is available in AI and EPS formats, including JPG preview.
banner picture
2024-02-29

Golden graduation cap vector material (EPS PNG)

This is a golden graduation cap vector material, available in EPS and PNG formats, including JPG preview.
PNG material
2024-02-27

Home Decor Cleaning and Repair Service Company Website Template

Home Decoration Cleaning and Maintenance Service Company Website Template is a website template download suitable for promotional websites that provide home decoration, cleaning, maintenance and other service organizations. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-05-09

Fresh color personal resume guide page template

Fresh color matching personal job application resume guide page template is a personal job search resume work display guide page web template download suitable for fresh color matching style. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-29

Designer Creative Job Resume Web Template

Designer Creative Job Resume Web Template is a downloadable web template for personal job resume display suitable for various designer positions. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28

Modern engineering construction company website template

The modern engineering and construction company website template is a downloadable website template suitable for promotion of the engineering and construction service industry. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28