korn HowTo - Linux / Unix Q & A from nixCraft

How To: Find Out KSH ( Korn Shell ) Version on Linux or Unix-like system

last updated March 15, 2017 in KSH Shell, Linux, UNIX

How do I check ksh version? How do I find out ksh version under UNIX like operating systems?

Linux: What is Dash ( /bin/dash ) Shell?

last updated May 28, 2011 in BASH Shell, Debian / Ubuntu

What is /bin/dash? I noticed that the default system shell /bin/sh was changed to /bin/dash. Why was this change made?

Shell Scripting: If Variable Is Not Defined, Set Default Variable

last updated July 27, 2009 in BASH Shell, KSH Shell, Programming

If var is defined AND NOT EMPTY, use var, otherwise set a default variable under Bash. For e.g. my script needs a parameter for output variable. It can be text or html. I set it as follows in my script

output=$1 # either text or html

However, sometime user forget to pass the parameter to my shell script and my enter logic fails. So how do I set default value to text, if no parameter passed?