UNIX related tutorial/FAQ

Check if a directory exists in Linux or Unix shell

last updated May 21, 2019 in BASH Shell, KSH Shell, Linux, UNIX

I need to check if a directory exists or not, within a shell script running on Linux or Unix-like system? How do I check if a directory exists in a shell script?

How to check hard drive health on FreeBSD

last updated May 20, 2019 in FreeBSD, Hardware, Troubleshooting, UNIX

How do I read my hard disk/SSD health using smartctl command on FreeBSD operating system? How can I hard drive health on FreeBSD and find out if my disk is dying?

How to rename multiple folders in Linux using command line

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

I am new to Linux programming and bash shell commands. I have a folder structure as dir1, dir2, dir3 and I would like to rename it as dir001, dir002, dir003. How do you rename multiple folders in Linux?

Linux bash exit status and how to set exit status in bash

last updated March 7, 2019 in BASH Shell, CentOS, Debian / Ubuntu, FreeBSD, Linux, Suse, UNIX

Can you explain bash exit status code? How do I set bash exit status in my Linux shell scripts?

How to override content type with Nginx web server

last updated January 21, 2019 in CentOS, Debian / Ubuntu, FreeBSD, Linux, Nginx, RedHat and Friends, Suse, UNIX

I configured Nginx server. However, it is sending the wrong content type. I need to force Nginx to send specific “Content-Type: text/xml; charset=UTF-8“. How do I configure Nginx to override content type for given URL location?

OpenBSD install MariaDB database server

last updated January 17, 2019 in MySQL, OpenBSD, UNIX

How do I install MariaDB database servers on OpenBSD Unix operating systems?

Bash shell find out if a variable has NULL value OR not

last updated December 27, 2018 in BASH Shell, FreeBSD, Korn Shell Scripting, KSH Shell, Linux, UNIX

I am a new to shell scripting. How do I check for NULL value in a Linux or Unix shell scripts?

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