ash: fix bad interaction of "stty -echo" + ASK_TERMINAL
function old new delta
read_line_input 4820 4886 +66
put_prompt 108 47 -61
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 66/-61) Total: 5 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index a997257..7bb3f2e 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -372,55 +372,14 @@
static void put_prompt(void)
{
+ unsigned w;
+
out1str(cmdedit_prompt);
fflush_all();
-#if ENABLE_FEATURE_EDITING_ASK_TERMINAL
- {
- /* Ask terminal where is the cursor now.
- * lineedit_read_key handles response and corrects
- * our idea of current cursor position.
- * Testcase: run "echo -n long_line_long_line_long_line",
- * then type in a long, wrapping command and try to
- * delete it using backspace key.
- * Note: we print it _after_ prompt, because
- * prompt may contain CR. Example: PS1='\[\r\n\]\w '
- */
- /* Problem: if there is buffered input on stdin,
- * the response will be delivered later,
- * possibly to an unsuspecting application.
- * Testcase: "sleep 1; busybox ash" + press and hold [Enter].
- * Result:
- * ~/srcdevel/bbox/fix/busybox.t4 #
- * ~/srcdevel/bbox/fix/busybox.t4 #
- * ^[[59;34~/srcdevel/bbox/fix/busybox.t4 # <-- garbage
- * ~/srcdevel/bbox/fix/busybox.t4 #
- *
- * Checking for input with poll only makes the race narrower,
- * I still can trigger it. Strace:
- *
- * write(1, "~/srcdevel/bbox/fix/busybox.t4 # ", 33) = 33
- * poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout) <-- no input exists
- * write(1, "\33[6n", 4) = 4 <-- send the ESC sequence, quick!
- * poll([{fd=0, events=POLLIN}], 1, 4294967295) = 1 ([{fd=0, revents=POLLIN}])
- * read(0, "\n", 1) = 1 <-- oh crap, user's input got in first
- */
- struct pollfd pfd;
-
- pfd.fd = STDIN_FILENO;
- pfd.events = POLLIN;
- if (safe_poll(&pfd, 1, 0) == 0) {
- S.sent_ESC_br6n = 1;
- out1str("\033" "[6n");
- fflush_all(); /* make terminal see it ASAP! */
- }
- }
-#endif
cursor = 0;
- {
- unsigned w = cmdedit_termw; /* volatile var */
- cmdedit_y = cmdedit_prmt_len / w; /* new quasireal y */
- cmdedit_x = cmdedit_prmt_len % w;
- }
+ w = cmdedit_termw; /* read volatile var once */
+ cmdedit_y = cmdedit_prmt_len / w; /* new quasireal y */
+ cmdedit_x = cmdedit_prmt_len % w;
}
/* draw prompt, editor line, and clear tail */
@@ -1503,6 +1462,51 @@
* read_line_input and its helpers
*/
+#if ENABLE_FEATURE_EDITING_ASK_TERMINAL
+static void ask_terminal(void)
+{
+ /* Ask terminal where is the cursor now.
+ * lineedit_read_key handles response and corrects
+ * our idea of current cursor position.
+ * Testcase: run "echo -n long_line_long_line_long_line",
+ * then type in a long, wrapping command and try to
+ * delete it using backspace key.
+ * Note: we print it _after_ prompt, because
+ * prompt may contain CR. Example: PS1='\[\r\n\]\w '
+ */
+ /* Problem: if there is buffered input on stdin,
+ * the response will be delivered later,
+ * possibly to an unsuspecting application.
+ * Testcase: "sleep 1; busybox ash" + press and hold [Enter].
+ * Result:
+ * ~/srcdevel/bbox/fix/busybox.t4 #
+ * ~/srcdevel/bbox/fix/busybox.t4 #
+ * ^[[59;34~/srcdevel/bbox/fix/busybox.t4 # <-- garbage
+ * ~/srcdevel/bbox/fix/busybox.t4 #
+ *
+ * Checking for input with poll only makes the race narrower,
+ * I still can trigger it. Strace:
+ *
+ * write(1, "~/srcdevel/bbox/fix/busybox.t4 # ", 33) = 33
+ * poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout) <-- no input exists
+ * write(1, "\33[6n", 4) = 4 <-- send the ESC sequence, quick!
+ * poll([{fd=0, events=POLLIN}], 1, 4294967295) = 1 ([{fd=0, revents=POLLIN}])
+ * read(0, "\n", 1) = 1 <-- oh crap, user's input got in first
+ */
+ struct pollfd pfd;
+
+ pfd.fd = STDIN_FILENO;
+ pfd.events = POLLIN;
+ if (safe_poll(&pfd, 1, 0) == 0) {
+ S.sent_ESC_br6n = 1;
+ out1str("\033" "[6n");
+ fflush_all(); /* make terminal see it ASAP! */
+ }
+}
+#else
+#define ask_terminal() ((void)0)
+#endif
+
#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
static void parse_and_put_prompt(const char *prmt_ptr)
{
@@ -1822,8 +1826,9 @@
bb_error_msg("cur_history:%d cnt_history:%d", state->cur_history, state->cnt_history);
#endif
- /* Print out the command prompt */
+ /* Print out the command prompt, optionally ask where cursor is */
parse_and_put_prompt(prompt);
+ ask_terminal();
read_key_buffer[0] = 0;
while (1) {