UNIX related tutorial/FAQ

How do I count how many processes are running in Linux?

How do I see how many processes are running in Linux? How can count all running processes in Linux?

last updated December 20, 2019 in Linux, Mac OS X, Troubleshooting, UNIX, Windows

How do I remove Santa Hat in VLC media player that displayed during Christmas time during 18th December to 1st January?

last updated December 12, 2019 in Linux, Networking, UNIX, Windows

How do I see Time-To-Live (TTL) for a DNS record using Linux, macOS, *BSD, or Unix-like systems command line option? How do I find my DNS TTL?

last updated December 11, 2019 in Linux, Networking, Troubleshooting, UNIX

How do I test and validate DNSSEC using the dig command line under Linux, macOS, *BSD, and Unix-like systems?

How do I enable and configure TLS 1.2 and 1.3 only in Nginx web server?

last updated November 19, 2019 in BASH Shell, Linux, UNIX

I need to find and return the PID of the last command executed in Linux. How do I return the PID of command in Linux?

last updated November 14, 2019 in BASH Shell, Linux, Mac OS X, UNIX

How do I extract filename and extension in the Bash shell script from the given path? How can I get filename from the path under the bash shell?