# Command line history gone

**URL:** <https://swi-prolog.discourse.group/t/command-line-history-gone/9365>\
**Category:** General\
**Created:** [October 30, 2025, 3:40pm UTC](https://swi-prolog.discourse.group/t/command-line-history-gone/9365 "2025-10-30T15:40:04Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![stassa.p](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/stassa.p/32/712_2.png) [@stassa.p](https://swi-prolog.discourse.group/u/stassa.p)\
**Post date:** [October 30, 2025, 3:40pm UTC](https://swi-prolog.discourse.group/t/command-line-history-gone/9365/1 "2025-10-30T15:40:04Z")

</div>

I reported some issues I had with the new SWI version 3.33 in this thread:

> [@Progressing the SWI-Prolog environment](https://swi-prolog.discourse.group/t/progressing-the-swi-prolog-environment/9090/39):
>
> Hm. Just realised that the new Open File dialog isn’t navigable with the keyboard. Is that … permanent? I really try to avoid touching the mouse as much as possible (wrists). Besides, is there an option to have Open File open the OS file explorer, instead of its own file navigator? It would be nice to be able to see a graphical representation of the file system and also decide whether to show/hide hidden files etc. Edit: More observations. The key bindings I was used to no longer work on wind…

To be able to work as fast as before while I get used to the new Epilog console and editor, I’ve re-installed my previous Prolog version, 9.3.24, alongside the new one. _After_ I did that, I noticed that I no longer have any command-line history in any of my Prolog projects.

What I mean by that is that up-arrow doesn’t fill in any commands, and `?- !!.` says there’s nothing there:

```prolog
1 ?- !!.
! No such event
! No such event
1 ?-

```

This is in the 9.3.24 SWI-Prolog console (in the SWI IDE). That is, not only my old history is gone, apparently, no new history is created. But that’s only in the SWI-Prolog console. If I start SWI in the windows powershell terminal, I do get history, but only for new commands (i.e. ones I gave after installing v.3.33). Unfortunately the powershell console doesn’t give me any tab completion so I generally prefer the SWI console.

The same happens for v.3.33: no history in the Epilog console, only recent history in the powershell command line.

I am guessing that installing v.3.33 somehow messed up the Prolog history on a machine-wide scale. Is there any way to get it back?

Thanks!

P.S. I’m starting a new thread on this issue since I don’t know if it’s relevant to v.3.33. Sorry if I should have left it in the old topic and please merge back if so. Thanks!

Edit:

I forgot to say that, after I noticed the missing history I added this line to my user init.pl file :

```prolog
:- set_prolog_flag(history, 50).

```

This flag is reported correctly in both version 3.24 and 3.33:

```prolog
2 ?- current_prolog_flag(history,V).
V = 50.

```

But it doesn’t do what it says in either version.
