How to delete files containing a character or number/digit in their filename on Linux or Unix

I am a new Linux system user. How do I delete file containing a character ‘a’ or ‘z’ in their filename or digit such as ‘4’ or ‘2’ in their filename on Linux or Unix…

How To Set Up a Firewall with PF on FreeBSD to Protect a Web Server

I am a new FreeBSD server user and moved from netfilter on Linux. How do I setup a firewall with PF on FreeBSD server to protect a web server with single public IP address and…

How to find and replace text/IP address with Ansible

I need to find an IP address in the sshd_config file and replace with a fresh one for over 100+ VMs. How do I use Ansible to do so? Is it possible to search replace…

How to find disk I/O latency with ioping monitoring tool on Linux

H ow do I monitor disk I/O latency in real time on Linux, FreeBSD, OpenBSD, and MacOS operating system?   You can use ioping tool to monitor I/O latency in real time. It shows disk…

How to find bash shell function source code on Linux/Unix

I am a new Linux server user. I cannot figure out how to find out the source code of a bash function named foo() which is defined. How to locate the file where a bash…

userdel: user vivek is currently used by process 749 error and fix on Linux

I am trying to delete a user named vivek using the userdel command as follows userdel -r vivek userdel: user vivek is currently used by process 749 How do I fix this problem and delete…

How to install xfs and create xfs file system on Debian/Ubuntu Linux

I recently switched to a Ubuntu/Debian Linux server from a CentOS/RHEL 7.x. How do I install mkfs.xfs command on a Debian/Ubuntu Linux server? How do I create and manage file XFS file system on a…

How to write/create a Ubuntu .iso to a bootable USB device on Linux using dd command

I downloaded a Ubuntu .iso file named artful-desktop-amd64.iso on a Debian Linux system. How do I write or burn a Ubuntu .iso to a USB device for installation purpose from Linux terminal?   You need…

How to install or compile GIMP filters/plugins/extensions on Linux

H ow do I install or compile new GIMP filters on a Ubuntu or Debian or Fedora or CentOS Linux desktop system?   GNU Image Manipulation Program (GIMP) is an open source and advanced picture…

How to install curl command on a Ubuntu Linux

I am a new Ubuntu Linux user. I switched from Apple MacOS/Macbook and I trying to run the curl command from a shell script but getting the following error: bash: curl: command not found How…