Installing KSH on Debian / Ubuntu serer or desktop

Open a terminal and then type the following apt-get command to install the package:
$ sudo apt-get install ksh
OR

Sample outputs:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  ksh
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 1,527 kB of archives.
After this operation, 3,191 kB of additional disk space will be used.
Get:1 http://mirrors.service.networklayer.com/ubuntu/ precise/universe ksh amd64 93u-1 [1,527 kB]
Fetched 1,527 kB in 0s (1,988 kB/s)
Selecting previously unselected package ksh.
(Reading database ... 82257 files and directories currently installed.)
Unpacking ksh (from .../archives/ksh_93u-1_amd64.deb) ...
Processing triggers for man-db ...
Setting up ksh (93u-1) ...
update-alternatives: using /bin/ksh93 to provide /bin/ksh (ksh) in auto mode.

Task: Finding ksh location

To find out path to the ksh, type:
$ whereis ksh
OR use the grep command as follows:
$ grep --color ksh /etc/shells
Sample outputs:

Task: Setting ksh as a default shell

The superuser (root) may change the login shell for any account using any one of the following syntax:
$ sudo chsh -s /bin/ksh UserNameHere
In this example, set default login shell to /bin/ksh for nixcraft user:
$ sudo chsh -s /bin/ksh nixcraft
Regular user can type the following command to change their shell to the ksh:
$ chsh -s /bin/ksh
$ grep nixcraft /etc/passwd
Sample outputs (when prompted enter your own password):

/bin/ksh93

To see ksh version, type:
$ ksh --version
Sample outputs:

  version         sh (AT&T Research) 93u 2011-02-08

Writing your first ksh script

Create a file called test.ksh using a text editor:

#!/bin/ksh
# Name: test.ksh (Debian/Ubuntu edition)
# Purpose: My first ksh script 
# Author: nixCraft <www.cyberciti.biz> under GPL v2.x+
# ------------------------------------------------------------------------
# set variables 
FILE="/etc/passwd"
NOW="$(date)"
HOSTNAME="`hostname`"
USERS_ACCOUNT="$(wc -l $FILE)"
OS="$(lsb_release -d | awk  '{ print $2 " version " $3}')"
#OS="$(lsb_release -d | awk -F':' '{ print $2 }')"
 
# Greet user
print "Hi, $USER. I'm $0. I'm $SHELL script running on $HOSTNAME at $NOW." 
print 
print "*** User accounts: $USERS_ACCOUNT"
print "*** Current working directory: $PWD"
print "*** OS: $OS"
 
print "*** Running for loop test just for fun:"
for x in {1..3}
do
    print "Welcome $x times."
done

Save and close the file. Run it as follows:

chmod +x test.sh
./test.sh

Sample outputs:

See also:

• CentOS / RHEL / Fedora Linux: Install KSH
• See man pages for more info whereis(1)