How to send email in Linux using command line

The key differences between CentOS and Ubuntu are: origin (CentOS originates from Red Hat, for enterprises; Ubuntu originates from Debian, for individuals), package management (CentOS uses yum, focusing on stability; Ubuntu uses apt, for high update frequency), support cycle (CentOS provides 10 years of support, Ubuntu provides 5 years of LTS support), community support (CentOS focuses on stability, Ubuntu provides a wide range of tutorials and documents), uses (CentOS is biased towards servers, Ubuntu is suitable for servers and desktops), other differences include installation simplicity (CentOS is thin)

CentOS has been discontinued, alternatives include: 1. Rocky Linux (best compatibility); 2. AlmaLinux (compatible with CentOS); 3. Ubuntu Server (configuration required); 4. Red Hat Enterprise Linux (commercial version, paid license); 5. Oracle Linux (compatible with CentOS and RHEL). When migrating, considerations are: compatibility, availability, support, cost, and community support.

CentOS installation steps: Download the ISO image and burn bootable media; boot and select the installation source; select the language and keyboard layout; configure the network; partition the hard disk; set the system clock; create the root user; select the software package; start the installation; restart and boot from the hard disk after the installation is completed.

How to use Docker Desktop? Docker Desktop is a tool for running Docker containers on local machines. The steps to use include: 1. Install Docker Desktop; 2. Start Docker Desktop; 3. Create Docker image (using Dockerfile); 4. Build Docker image (using docker build); 5. Run Docker container (using docker run).

Docker uses Linux kernel features to provide an efficient and isolated application running environment. Its working principle is as follows: 1. The mirror is used as a read-only template, which contains everything you need to run the application; 2. The Union File System (UnionFS) stacks multiple file systems, only storing the differences, saving space and speeding up; 3. The daemon manages the mirrors and containers, and the client uses them for interaction; 4. Namespaces and cgroups implement container isolation and resource limitations; 5. Multiple network modes support container interconnection. Only by understanding these core concepts can you better utilize Docker.

VS Code system requirements: Operating system: Windows 10 and above, macOS 10.12 and above, Linux distribution processor: minimum 1.6 GHz, recommended 2.0 GHz and above memory: minimum 512 MB, recommended 4 GB and above storage space: minimum 250 MB, recommended 1 GB and above other requirements: stable network connection, Xorg/Wayland (Linux)

Docker process viewing method: 1. Docker CLI command: docker ps; 2. Systemd CLI command: systemctl status docker; 3. Docker Compose CLI command: docker-compose ps; 4. Process Explorer (Windows); 5. /proc directory (Linux).

Troubleshooting steps for failed Docker image build: Check Dockerfile syntax and dependency version. Check if the build context contains the required source code and dependencies. View the build log for error details. Use the --target option to build a hierarchical phase to identify failure points. Make sure to use the latest version of Docker engine. Build the image with --t [image-name]:debug mode to debug the problem. Check disk space and make sure it is sufficient. Disable SELinux to prevent interference with the build process. Ask community platforms for help, provide Dockerfiles and build log descriptions for more specific suggestions.