fwiw you can just use
bind -m '^L'=^Uclear'^J^Y' Todd C. Miller(todd.mil...@sudo.ws) on 2018.06.16 06:37:03 -0600: > On Tue, 12 Jun 2018 02:35:57 +0200, Alexander Hall wrote: > > > The diff below uses system(3) to call /usr/bin/clear, fiddling with > > *env() to make sure the current TERM value is propagated. The error > > handling is deliberately sparse, since I don't know what the reasonable > > error actions would be. > > > > It's quite possible there already exists a better function to call > > within the ksh code already, but I was unable to figure out which if so. > > Using system() within ksh seems wrong. How about this instead? > > - todd > > Index: bin/ksh/emacs.c > =================================================================== > RCS file: /cvs/src/bin/ksh/emacs.c,v > retrieving revision 1.84 > diff -u -p -u -r1.84 emacs.c > --- bin/ksh/emacs.c 16 Jan 2018 17:17:18 -0000 1.84 > +++ bin/ksh/emacs.c 16 Jun 2018 12:31:59 -0000 > @@ -146,6 +146,7 @@ static int isu8cont(unsigned char); > /* proto's for keybindings */ > static int x_abort(int); > static int x_beg_hist(int); > +static int x_clear_screen(int); > static int x_comp_comm(int); > static int x_comp_file(int); > static int x_complete(int); > @@ -202,6 +203,7 @@ static int x_debug_info(int); > static const struct x_ftab x_ftab[] = { > { x_abort, "abort", 0 }, > { x_beg_hist, "beginning-of-history", 0 }, > + { x_clear_screen, "clear-screen", 0 }, > { x_comp_comm, "complete-command", 0 }, > { x_comp_file, "complete-file", 0 }, > { x_complete, "complete", 0 }, > @@ -1004,12 +1006,19 @@ x_draw_line(int c) > { > x_redraw(-1); > return KSTD; > +} > > +static int > +x_clear_screen(int c) > +{ > + x_redraw(-2); > + return KSTD; > } > > -/* Redraw (part of) the line. If limit is < 0, the everything is redrawn > - * on a NEW line, otherwise limit is the screen column up to which needs > - * redrawing. > +/* Redraw (part of) the line. > + * A non-negative limit is the screen column up to which needs > + * redrawing. A limit of -1 redraws on a new line, while a limit > + * of -2 (attempts to) clear the screen. > */ > static void > x_redraw(int limit) > @@ -1018,9 +1027,20 @@ x_redraw(int limit) > char *cp; > > x_adj_ok = 0; > - if (limit == -1) > + if (limit == -2) { > + char *term = str_val(global("TERM")); > + int ret = -1; > + if (term && *term) { > + Source *sold = source; > + ret = command("/usr/bin/clear", 0); > + source = sold; > + } > + if (ret != 0) > + x_e_putc('\n'); > + } > + else if (limit == -1) > x_e_putc('\n'); > - else > + else if (limit >= 0) > x_e_putc('\r'); > x_flush(); > if (xbp == xbuf) { > Index: bin/ksh/ksh.1 > =================================================================== > RCS file: /cvs/src/bin/ksh/ksh.1,v > retrieving revision 1.200 > diff -u -p -u -r1.200 ksh.1 > --- bin/ksh/ksh.1 30 May 2018 21:20:52 -0000 1.200 > +++ bin/ksh/ksh.1 16 Jun 2018 12:29:34 -0000 > @@ -4690,6 +4690,10 @@ Moves the cursor to the beginning of the > Uppercase the first character in the next > .Ar n > words, leaving the cursor past the end of the last word. > +.It clear-screen: > +Attempts to clears the screen by invoking > +.Xr clear 1 > +and redraws the prompt and current input line. > .It comment: ^[# > If the current line does not begin with a comment character, one is added at > the beginning of the line and the line is entered (as if return had been >