Is SU (ESC[<n>S) supposed to erase text?

[vefatica]

I ultimately want to scroll so that the current command line is at the top of the viewport. I thought I could do that with some combination of SU and cursor placement. Not worrying about cursor placement, I noticed this.

Having just executed DIR I'm at the bottom (line 42) of the viewport.

If I issue echo ^e[37S 37 lines of the history (now out of the viewport) are erased. And it's NOT the last 37 lines that were erased! Here's the tail end of what's now in the history.

In contrast, if, in the same situation, I issue echo ^e[35S nothing is erased.

What's going on there? The docs don't mention SU erasing anything (especially in such an odd way). And it would be useful to scroll without losing any recent history.

Is there another strategy for scrolling, without losing anything, so the current command line is at the top.

[j4james]

What you're trying to do should ideally work, and we've already got an issue tracking that (#11078). But even if it were fixed on Windows Terminal, using SU this way is not generally reliable, so it's not something I would recommend.

Is there another strategy for scrolling, without losing anything, so the current command line is at the top.

The most reliable solution is just writing out a bunch of LF characters at the bottom of the screen.

[vefatica]

I see. Thanks for the suggestion, @j4james. It works nicely. I should have thought of it. :-)