Description #
KornShell (ksh) is a Unix shell developed by David Korn at Bell Labs. It combines features from the Bourne shell (sh) and the C shell (csh) while adding powerful programming capabilities like associative arrays, built-in arithmetic, and job control.
History #
KornShell was introduced in the early 1980s and became the default shell on many commercial Unix systems. It was designed to improve shell scripting performance and provide better programming structures. Over the years, various versions have emerged, including ksh88 and ksh93, the latter being open-sourced in 2000.
Key milestones:
- Early 1980s: Developed at Bell Labs
- 1988:
ksh88becomes widely adopted in enterprise Unix - 1993:
ksh93adds major enhancements and is open-sourced - Still used in legacy systems and enterprise automation
Hello World Code #
#!/bin/ksh
echo "Hello, World!"How to Run #
In a Unix/Linux terminal:
- Save the code in a file named
hello.ksh - Make the file executable:
chmod +x hello.ksh- Run the script:
./hello.kshKey Concepts #
- Compatible with Bourne shell syntax (
sh) - Supports variables, functions, conditionals, loops
- Allows associative arrays (in
ksh93) - Arithmetic evaluation using
(( )) - Supports here documents for multi-line input
- Built-in support for job control (
fg,bg) - History and command-line editing
- Provides better performance than older shells
- Script portability across Unix systems
- Still used in financial, telecom, and government systems
Try It Online #
- Replit – KornShell (choose Bash, manually switch to
ksh) - OnlineGDB – Unix Shell (use ksh)
- Or install locally via
apt install kshorbrew install ksh
Fun Facts #
- Named after its creator, David Korn
- Inspired features in Bash and other modern shells
- Once bundled with major Unix systems like AIX, HP-UX, and Solaris
- Many older scripts in banking systems still use ksh
ksh93was maintained by Bell Labs as part of the AST (Advanced Software Technology) project
