The “disown” command in Linux and Unix is used to remove a job from the control of the terminal and shell. When a job is disowned, it will continue to run in the background even if the terminal is closed, or the user logs out. Here are some examples of how to use the “disown” … Read more

To configure a network interface as a bridge in OpenBSD, you need to use the “ifconfig” command. A bridge is a device that connects multiple network interfaces together, allowing traffic to be passed between them. Here’s an example of how to configure a bridge interface in OpenBSD: Create the bridge interface: ifconfig bridge0 create Add … Read more

To sort the output of the “ls” command by file size, you can use the “ls” command with the “-S” option. The “-S” option sorts the files and directories by size, with the largest files listed first. Here’s an example of how to use the “ls” command to sort files by size: ls -lS This … Read more

To convert an AVI file to Apple iPod/iPhone MP4 (M4V) format on Linux, you can use the HandBrake tool. HandBrake is an open-source, multithreaded video transcoder that can be used to convert videos from one format to another. Here’s how you can use HandBrake to convert an AVI file to MP4 format on Linux: Install … Read more

To change the outgoing IP address for a Squid proxy server, you can use the “tcp_outgoing_address” directive in the Squid configuration file. This directive specifies the IP address that Squid should use as the source address for outgoing TCP connections. Here’s how you can change the outgoing IP address for a Squid proxy server: Open … Read more

To set up a firewall for a web server using iptables in Linux, you can use the following steps: Flush existing rules: sudo iptables -F Set the default policy to drop incoming and forward traffic: sudo iptables -P INPUT DROP sudo iptables -P FORWARD DROP Allow incoming traffic on the loopback interface: sudo iptables -A … Read more

To change the OpenSSH port number in Red Hat Enterprise Linux (RHEL) 5/6, you can modify the SSH daemon’s configuration file, which is located at “/etc/ssh/sshd_config”. Here’s how you can change the OpenSSH port number: Open the “/etc/ssh/sshd_config” file using a text editor: sudo vi /etc/ssh/sshd_config Find the line that starts with “Port” and change … Read more

To find out which processes are using swap space in Linux, you can use the “top” or “pmap” command. “top” command: The “top” command provides an interactive display of system information, including a list of processes and their associated resource usage. You can use the “top” command to see the amount of swap space being … Read more

In the Korn shell (ksh), you can redirect both standard output (stdout) and standard error (stderr) to a file using the following syntax: command > file.txt 2>&1 In this example, “command” is the command you want to run, and “file.txt” is the name of the file to which the output will be redirected. The “2>&1” … Read more

A shell script is a text file that contains shell commands, and can be executed on a Linux system. Here are the steps to run a shell script in Linux: Make the script executable: chmod +x script.sh Replace “script.sh” with the actual name of your shell script file. This step sets the execute permission on … Read more