Here is a basic script in bash for looping through the contents of a file using a while loop: #!/bin/bash # specify the file you want to read filename=”file.txt” # open the file using a file descriptor # the -r option is to read the file exec 3<&0 exec 0<$filename # while loop to read … Read more

In a Linux or Unix shell, you can create an infinite loop using the while loop. The syntax for the while loop is as follows: while true; do [command1] [command2] … done Here, true is a command that always returns a successful exit status (0), so the loop will continue to execute indefinitely until it … Read more

In OpenBSD, you can see information about the PCI devices on your system by using the “pcictl” command. This command provides information about the PCI buses, PCI devices, and PCI functions present on the system. To display information about all PCI devices on the system, run the following command: pcictl dump You can also display … Read more

To disable a user account on Linux, you can use the usermod command. The usermod command allows you to modify the attributes of a user account. To disable a user account, you can add the -L option to the usermod command. For example, to disable the user account named user1, you would run the following … Read more

To manage the Nginx web server on Ubuntu Linux, you can use the following commands: Start Nginx: sudo service nginx start Restart Nginx: sudo service nginx restart Stop Nginx: sudo service nginx stop Note that these commands require root privileges, so you’ll need to use sudo to run them.

The “SIOCADDRT: File exists” error message in Ubuntu (and other Linux distributions) occurs when you try to add a route to the system routing table that already exists. This error message indicates that the system is unable to add the new route because it conflicts with an existing route. To resolve this issue, you can … Read more

The devpts file system is a virtual file system in Linux used to provide access to the terminal’s pseudo-terminal master-slave pairs. To mount the devpts file system on /dev/pts, use the following command: mount -t devpts devpts /dev/pts This will mount the devpts file system on /dev/pts so that you can use pseudo-terminals in your … Read more

You can configure automatic logout in the bash shell by setting the TMOUT environment variable. The value of this variable specifies the number of seconds of inactivity after which the shell will log out automatically. To set automatic logout for your current session, you can use the following command: export TMOUT=300 This will set automatic … Read more

SSH X11 Forwarding can be slow, especially over long distances or low-bandwidth connections. To speed up SSH X11 Forwarding, you can make the following optimizations: Compression: Enable compression on the SSH connection by adding the -C option to the ssh command. $ ssh -C user@host Forwarding optimization: To optimize the X11 forwarding, add the following … Read more

To kill an unresponsive or hung SSH session in Linux or UNIX, you can use the following command: $ kill -9 <PID> Replace <PID> with the process ID of the SSH session. You can find the PID by using the following command: $ ps -ef | grep ssh This will list all the running SSH … Read more