In Linux or Unix, you can list the contents of a directory and its subdirectories recursively using the ls command with the -R or –recursive option. Here’s an example: ls -R /path/to/directory This will list the contents of the directory /path/to/directory and all its subdirectories, displaying the names of files and directories in a tree-like … Read more
You can use the lsof (list open files) command in Linux to find out which files (also called descriptors) are open by a process. The lsof command displays a list of all open files and the processes that have them open. To display the open files for a specific process, you can run the following … Read more
In the SysVinit init system, which is used in many Linux and Unix distributions, there are several commands to control system services: restart: The restart command stops the service and then starts it again. This is useful when you want to apply changes to the service’s configuration. service <service_name> restart reload: The reload command reloads … Read more
In a Linux or Unix shell script, you can get the current year using the date command. For example: current_year=$(date +%Y) The date command is used to print or set the system date and time, and the +%Y option specifies that the year in the format YYYY should be displayed. The output of the date … Read more
To install OpenSSH server on Debian Linux 9 (Stretch), 10 (Buster), or 11 (Bullseye), you can follow these steps: Update the package list by running the following command: sudo apt-get update Install the OpenSSH server package: sudo apt-get install openssh-server Check that the SSH service is running: sudo systemctl status ssh If the service is … Read more
To install TrueType fonts in Debian Linux for use with Xorg, you can follow these steps: Install the necessary package: sudo apt-get install ttf-mscorefonts-installer Copy the TrueType fonts you want to install to the font directory /usr/share/fonts/truetype/. Update the font cache by running the following command: sudo fc-cache -fv Restart the X server by logging … Read more
You can check the version of the Linux kernel that’s currently running on your Ubuntu system using the following command: uname -r The uname command provides information about the system and its environment, and the -r option specifically requests the release information, which is the version of the Linux kernel. You can also use the … Read more
Here are some common examples of the host command in Linux and Unix: To perform a simple DNS lookup for a hostname, you can run the following command: host example.com To perform a reverse DNS lookup for an IP address, you can run the following command: host 8.8.8.8 You can also specify the DNS server … Read more
The dig command in Linux and Unix is used to query the Domain Name System (DNS) to retrieve information about hostnames, IP addresses, and other DNS-related information. The dig command can be used to perform various types of DNS lookups, such as checking the A (address) record for a hostname, the MX (mail exchange) record … Read more
There are several ways to find memory usage information on a CentOS Linux system. Here are some common commands: free: This command displays the amount of free and used memory in the system, as well as the swap space usage. The output is in kilobytes: $ free -h The -h option displays the output in … Read more