This adds a "clear-screen" editing command to the emacs editing mode.
This is the same name as bash and zsh uses, and then I stopped looking.
The default binding of 'redraw' remains for ^L, for now anyway, so
you'll need to run
$ bind ^L=clear-screen"
when testing.
$CLEARSTR can be set to an arbitrary character sequence for clearing the
screen, should ^[[H^[[J not fit the bill. For example,
$ CLEARSTR=$(clear)
Not sure we want or need this, or what could possibly be a better name
for it.
Thoughts? OK?
/Alexander
Index: emacs.c
===================================================================
RCS file: /cvs/src/bin/ksh/emacs.c,v
retrieving revision 1.84
diff -u -p -r1.84 emacs.c
--- emacs.c 16 Jan 2018 17:17:18 -0000 1.84
+++ emacs.c 5 Jun 2018 22:03:49 -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 +1027,15 @@ x_redraw(int limit)
char *cp;
x_adj_ok = 0;
- if (limit == -1)
+ if (limit == -2) {
+ char *clearstr = str_val(global("CLEARSTR"));
+ if (clearstr == null)
+ clearstr = "\033[H\033[J";
+ x_e_puts(clearstr);
+ }
+ else if (limit == -1)
x_e_putc('\n');
- else
+ else if (limit >= 0)
x_e_putc('\r');
x_flush();
if (xbp == xbuf) {
Index: ksh.1
===================================================================
RCS file: /cvs/src/bin/ksh/ksh.1,v
retrieving revision 1.200
diff -u -p -r1.200 ksh.1
--- ksh.1 30 May 2018 21:20:52 -0000 1.200
+++ ksh.1 5 Jun 2018 22:03:49 -0000
@@ -1345,6 +1345,8 @@ Also, the
.Ic cd
built-in command will display the resulting directory when a match is found
in any search path other than the empty path.
+.It Ev CLEARSTR
+If set, overrides the default escape sequence to clear the screen.
.It Ev COLUMNS
Set to the number of columns on the terminal or window.
Currently set to the
@@ -4690,6 +4692,12 @@ 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:
+Clears the screen and redraws the prompt and current input line.
+If the
+.Ev CLEARSTR
+parameter is set, it is used to clear the screen.
+Otherwise, a default escape sequence (^[[H^[2J) is used.
.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
