PhxBUG - Phoenix BSD User Group

Recent releases of OpenBSD ship with a modified version of the public domain Korn shell (pdksh). ksh evolved as the de facto POSIX shell when it was written to address some of the shortcomings that the venerable Bourne shell had. On OpenBSD, /bin/sh is really a renamed copy of /bin/ksh that provides very consistent behavior with the original Bourne shell.

OpenBSD's ksh supports command line editing, history, useful builtins, small footprint, and several other features that make it an attractive alternative to those used to BASH on GNU/Linux. Since it is a static binary and located directly under /bin, it is a suitable shell for both regular users and root alike.

For more information about ksh, the following resources are suggested:

• The ksh(1) manual page.
• Learning the Korn Shell, Second Edition. (O'Reilly) (Amazon). Although this book covers the traditional Korn shell, the information presented applies to PDKSH as well, with the exception of mostly minor differences in implementation.

Earlier releases of OpenBSD provided the C shell (/bin/csh) as the default shell on the system.