Re: Ctrl-L cleaning the screen

[Thomas Dickey]

On Sun, Jun 23, 2024 at 03:19:57AM -0400, Steve Litt wrote:
> Thomas Dickey said on Sat, 22 Jun 2024 17:19:54 -0400
> 
> >On Fri, Jun 21, 2024 at 07:01:44AM +1000, Michael D. Setzer II wrote:
> 
> >> Just wondering if the Ctrl-L would clean screen?  
> >
> >A few terminals (mostly emulators actually) will clear the screen on
> >^L. DEC's hardware terminals were not among those; xterm likewise.
> 
> I don't know if this is relevant to this discussion, but when I

no - retitled.

> designed the original UMENU () in 1999, my screen clear was 25
> newlines. I did this to work on absolutely any terminal, including a
> teletype.

25 lines is basically a PC artifact.

When I first got involved with form-feed, hard-copy was 66 lines.
That was before PCs.

https://invisible-island.net/xterm/xterm.faq.html#xterm_form_feed
https://invisible-island.net/personal/oldprogs.html#repaginator

Video terminals differ.  A VT100 has 24 lines, but the VT100-compatible
Bitgraph had 64 lines:

https://invisible-island.net/personal/oldprogs.html#bitgraph

bitgraph|bg2.0nv|bg3.10nv|BBN BitGraph 2.0 or later (normal video),
        xenl,
        cols#85, lines#64,
        bel=^G, clear=\E[H\E[J$<150>, cr=\r,
        csr=\E[%i%p1%d;%p2%dr, cub1=^H, cud1=\E[B, cuf1=\E[C,
        cup=%i\E[%p1%d;%p2%dH, cuu1=\E[A, dl1=\E[M$<2*>,
        ed=\E[J$<150>, el=\E[K$<2>, flash=\E[?5h$<200/>\E[?5l,
        ht=^I, il1=\E[L$<2*>, ind=\n$<280>, is2=\E>\E[?5l\E[?7h,
        kcub1=\E[D, kcud1=\E[B, kcuf1=\E[C, kcuu1=\E[A, kf1=\EOP,
        kf2=\EOQ, kf3=\EOR, kf4=\EOS, lf1=PF1, lf2=PF2, lf3=PF3,
        lf4=PF4, rc=\E8, rmkx=\E>, rmso=\E[m, sc=\E7, sgr0=\E[m,
        smkx=\E=, smso=\E[7m,

Terminal emulators can of course have lots of sizes, and it's been that
way a while.  This one dates back to the 1980s:

x10term|vs100-x10|xterm terminal emulator (X10 window system),
        OTbs, am, km, mir, msgr, xenl, xon,
        cols#80, it#8, lines#65,
        bold=\E[1m, clear=\E[H\E[2J, csr=\E[%i%p1%d;%p2%dr,
        cub1=^H, cud1=\n, cuf1=\E[C, cup=\E[%i%p1%d;%p2%dH,
        cuu1=\E[A, dch=\E[%p1%dP, dch1=\E[P, ed=\E[J, el=\E[K,
        home=\E[H, ht=^I, ind=\n, is2=\E\E[m\E[?7h\E[?1;4l, kbs=^H,
        kcub1=\EOD, kcud1=\EOB, kcuf1=\EOC, kcuu1=\EOA, kf1=\EOP,
        kf2=\EOQ, kf3=\EOR, kf4=\EOS, rev=\E[7m, ri=\EM, rmam=\E[?7l,
        rmir=\E[4l, rmkx=\E[?1l\E>, rmso=\E[m, rmul=\E[m,
        sgr0=\E[m, smam=\E[?7h, smir=\E[4h, smkx=\E[?1h\E=,
        smso=\E[7m, smul=\E[4m, use=ansi+idl,

-- 
Thomas E. Dickey <dickey@invisible-island.net>
https://invisible-island.net

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