UNIX – nixCraft

How to check and verify md5/sha1/sha256 checksums for Apple MacOS X when I download files

June 30, 2017June 30, 2017in BASH Shell, Mac OS X, Security, UNIX last updated June 30, 2017

Malware is becoming more and more common for macOS. I wanted to make sure file I downloaded files such as an ISO image or firmware are safe before install on my system. How do I verify md5 or sha1 or sha256 checksums for my Apple MacOS X when I download files from the Internet?

How to write Raspbian Jessie image file to SD cards on Apple macOS / OS X

June 27, 2017June 27, 2017in Linux, Mac OS X, Raspberry Pi, UNIX last updated June 27, 2017

I got a Raspberry PI 3 from my friend. I am a long term macOS user. How do I write Raspbian image file to SD card using macOS?

How to display countdown timer in bash shell script running on Linux/Unix

June 24, 2017June 24, 2017in BASH Shell, Linux, UNIX last updated June 24, 2017

I want to display a countdown before purging cache from CDN network. Is there an existing command to show a conuntdown from 30..1 as 30,29,28,…1 on Linux or Unix bash shell script?

How to add ZIL write and L2ARC read cache SSD devices in FreeNAS

June 24, 2017in File system, FreeBSD, FreeNAS, UNIX last updated June 24, 2017

How do I add the write cache called the ZIL and read cache called L2ARC to my my zroot volume? How do I extend my existing zroot volume with ZIL and L2ARC ssd disks of FreNSA server?

How to find and delete directory recursively on Linux or Unix-like system

June 20, 2017June 22, 2017in BASH Shell, Linux, UNIX last updated June 22, 2017

I type ‘find . -type d -iname foo -delete‘ command to find the foo directories and delete them. However, I am getting an error message that read as find: cannot delete './hourly.4/data/foo': Directory not empty on Linux server. How do delete directories based on find command output on Linux or Unix-like system?

How to run cron job every minute on Linux/Unix

June 18, 2017June 18, 2017in BASH Shell, Commands, Linux, UNIX last updated June 18, 2017

I want to run a cron job that should run a specific shell script /home/jobs/sync.cache.sh every minute. How do I use crontab to execute script every minute on Linux or Unix-like system?

How to redirect non-www to www HTTP / TLS /SSL traffic on Nginx

June 17, 2017June 17, 2017in Linux, Nginx, UNIX last updated June 17, 2017

I want ALL cyberciti.biz to go to www.cyberciti.biz for SEO and other reasons. I want ALL HTTP traffic to go to HTTPS. How do I redirect all HTTP/HTTPS non-www (e.g. domain name cyberciti.biz) traffic to www (e.g. domain name www.cyberciti.biz) when using Nginx web server?