Linux systemctl command The systemctl command is a new tool to control the systemd system and service. This is the replacement of old SysV init system management. Most of modern Linux operating systems are using this new tool. If you are working with CentOS 7, Ubuntu 16.04 or later or Debian 9 system. They have opted systemd now. Syntax systemctl [OPTION] [SERVICE] For this tutorial, All commands are written to show the service management of mysql service on Linux system. Where you can use mysql or mysql.service as a service…
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Linux Architecture
Linux Architecture The Linux system works basically on 4 layers. First view the diagram below, which is showing the architecture of a Linux System. Hardware − Hardware consists of all physical devices attached to the System. For example: Hard disk drive, RAM, Motherboard, CPU etc. Kernel − Kernel is the core component for any (Linux) operating system which directly interacts with the hardware. Shell − Shell is the interface which takes input from Users and sends instructions to the Kernel, Also takes the output from Kernel and send the result…
Read MoreWhat is Linux
Intoduction to Linux Linux is an opensource operating system, Similar to any other operating systems like Windows, MAC etc. An operating system is a program which manages the communication between user software and hardware. There are following major parts in a Linux system: kernel – A Linux Kernel is the core of any operating system, which directly interacts with the hardware. It manages all the system resources like “Memory”, “CPU”, “Processes” and Attached peripheral devices to the system. Bootloader – The Bootloader also called Boot Manager. A program that handles…
Read MoreLinux – chage
Linux chage command The chage command is used to set account expiration date for user. It also changes the time the user’s password will expire. Syntax: $ chage [options] LOGIN Examples:- #1 – Set Password Expiry Days of User Set the number of days to expire password after last change. It means the user will force to change its password after 15 days of last change. $ chage -M 15 testuser #2 – Set Account Password Expiry Warning Date You can also set the password expiry warning date. So that…
Read MoreLinux – cat
Linux cat command Linux cat command is used to display file content. You can also use this to create new files or copy file contents to other files. Syntax: $ cat file_name Examples: #1. Display File Content For example use the following command to list content of /etc/passwd file. $ cat /etc/passwd Output: root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin bin:x:2:2:bin:/bin:/usr/sbin/nologin sys:x:3:3:sys:/dev:/usr/sbin/nologin sync:x:4:65534:sync:/bin:/bin/sync games:x:5:60:games:/usr/games:/usr/sbin/nologin … #2. Display Multiple File Content You can also display the multiple file content in single command. $ cat /etc/passwd /etc/group #3. Display Line Numbers Use -n switch to display the…
Read MoreLinux – ls command
Linux ls command The ls command is used to list files and directories in filesystem. Login to your Linux system and open shell. Syntax ls [OPTION] [FILE] Examples Now type ls and press enter. This will show file names available in the current directory. ls Long Listing Files You can use -l switch to view the long listing of files. ls -l You can also specify the filename to get details for a specific file. ls -l myfile.txt List Hidden Files You can also use the -a switch with ls…
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