is there a way to re-load that console buffer temp files, created after the 'unlimited scrollback' option is selected?
I have the files like /tmp/konsole-xxxxx.history in the /tmp dir, but cannot figure out how to read them or re-load them

As for reading them, I'd assume they contain konsole's custom character-based metadata. You'd have to dig into konsole's source code to figure out how to read them (or transform them into something readable).

For re-loading them, do you intend to have konsole attach a previous session's scroll history to a new session's scroll history (or at least be able to recall the previous scroll history in some way)? I haven't heard of any terminal providing such a feature but it seems like it could be nice to have, in a similar way to having command history. Mostly it would be redundant with shell history except that it provides the actual output with the commands that were run.

yes, I want to re-load them into the console, so I can get the previous command output history.
Also, sometimes, when the scroll history is too big, the older parts cannot be scrolled to. I can see or guess which .history files are probably involved, but I cannot 're-load' them

As I mentioned, such a feature doesn't exist.
You can file a request to bugs.kde.org to have the feature added.

hello,

i have been trying to figure out what these files are. It seems only recently have i noticed the files. i am a regular command line type person, so a long time user of konsole. are these files important for the user and if not, how can i turn off their generation. seem to be a little ugly in operation, to me.

very old and stewped *nix developer from the k&r days....
allen

The output buffer files are configurable per-profile under the edit profile's Scrolling tab. Selecting Unlimited scrollback enables the files, while No scrollback and Fixed size scrollback store the scrollback in memory and shouldn't save anything to disk.