We had a guy retire on us, and the documentation left behind is a little on the light side. Need a little help identifying and using part an older client-server system.

The server itself is maintained by several excellent Unix admins. We are currently running AIX on the server side.

However, when we log in using the proprietary SSH client, we are greeted with a shell that looks familiar, but is strange in other ways. The shell itself seems to be KornShell:

echo $0

But the shell doesn't respond to normal shell commands (cannot tap up/down to recall recent commands, cannot backspace normally, no auto-complete with tab, etc.)

Recent commands are recalled using ESC + k

If the ESC key is tapped, the terminal stops responding to input until i, a, s, or cc are pressed (or k, as already mentioned brings up the most recent command).

To edit a recalled command we have to tap SHIFT + UP

Backspace is actually the RIGHT arrow, and to clear a typed command we have to hit SHIFT + RIGHT

The whence command is not available, and none of the techniques to discover the KSH version on this page worked.

Someone in our office suggested this is some kind of inline vi.

Does anyone else have any advice? Is there any documentation available?

  • 4
    probably a combination of set -o vi (you can get back with set -o emacs) and some incorrectly set $TERM variable (not matching the terminal emulation emulated by your SSH client). – mihi Nov 21 '17 at 20:35
  • @mihi This does favorably change the way the shell responds. Still having trouble figuring out how recent commands can be recalled (the Up arrow is not working), but at least the backspace key works normally. – JonathanDavidArndt Nov 23 '17 at 4:40
  • You should check out ~/.profile, ~/.kshrc, /etc/profile and the value of $ENV. Also read the man page for ksh. You will then find where set -o vi is being run among many other things. – jrw32982 supports Monica Nov 24 '17 at 17:45




This was discovered on a related question on the Unix & Linux SE:

How can I safely get the version of ksh? - Unix & Linux Stack Exchange

This revealed that we are running

Version M-11/16/88f

Maybe it's not that ancient after all!

  • As it turns out, your friendly Unix admins can install an up-to-date version of bash on AIX 7.1 by request. ksh is dead; long live ksh~ – JonathanDavidArndt Jan 11 '18 at 23:16

Try what $(which ksh)

For example, on a Solaris 8 box:

$ what $(which ksh)
        Version M-11/16/88i
        SunOS 5.8 Generic 110662-24 Apr 2007
  • For this, I get a huge, vomitous mass of information, 40+ lines long, mostly .c libraries. At the very end, there is an entry for vi.c, cmdksh, aix71B 1040A_71B followed by a datestamp from the year 2010. – JonathanDavidArndt Nov 21 '17 at 21:00
  • 1
    search through the spew for the 88 or 93 to see if you can narrow down the ksh version. – glenn jackman Nov 21 '17 at 21:42
  • 1
    And, I just had the same thought as mihi above: set -o emacs – glenn jackman Nov 21 '17 at 21:43
  • Really want to accept this answer. You still get my upvote. Even though this did not directly solve the problem, it still was extremely helpful. The command suggested actually works -- unlike many of the other suggestions around the webs. Thank you. You are a gentleman and a scholar. – JonathanDavidArndt Nov 23 '17 at 4:46

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