libbb/lineedit: try to make FEATURE_EDITING_ASK_TERMINAL less ugly
function old new delta
read_line_input 4809 4829 +20
lineedit_read_key 207 223 +16
put_prompt 110 117 +7
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 43/0) Total: 43 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 2e1bc5d..b4c3fd3 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -140,6 +140,9 @@
smallint newdelflag; /* whether delbuf should be reused yet */
CHAR_T delbuf[DELBUFSIZ]; /* a place to store deleted characters */
#endif
+#if ENABLE_FEATURE_EDITING_ASK_TERMINAL
+ smallint sent_ESC_br_n6;
+#endif
/* Formerly these were big buffers on stack: */
#if ENABLE_FEATURE_TAB_COMPLETION
@@ -371,7 +374,8 @@
{
out1str(cmdedit_prompt);
fflush(NULL);
- if (ENABLE_FEATURE_EDITING_ASK_TERMINAL) {
+#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.
@@ -405,10 +409,12 @@
pfd.fd = STDIN_FILENO;
pfd.events = POLLIN;
if (safe_poll(&pfd, 1, 0) == 0) {
+ S.sent_ESC_br_n6 = 1;
out1str("\033" "[6n");
fflush(NULL); /* make terminal see it ASAP! */
}
}
+#endif
cursor = 0;
{
unsigned w = cmdedit_termw; /* volatile var */
@@ -1666,20 +1672,24 @@
/* Note: read_key sets errno to 0 on success: */
ic = read_key(STDIN_FILENO, read_key_buffer);
- if (ENABLE_FEATURE_EDITING_ASK_TERMINAL
- && cursor == 0 /* otherwise it may be bogus */
- && (int32_t)ic == KEYCODE_CURSOR_POS
+#if ENABLE_FEATURE_EDITING_ASK_TERMINAL
+ if ((int32_t)ic == KEYCODE_CURSOR_POS
+ && S.sent_ESC_br_n6
) {
- int col = ((ic >> 32) & 0x7fff) - 1;
- if (col > cmdedit_prmt_len) {
- cmdedit_x += (col - cmdedit_prmt_len);
- while (cmdedit_x >= cmdedit_termw) {
- cmdedit_x -= cmdedit_termw;
- cmdedit_y++;
+ S.sent_ESC_br_n6 = 0;
+ if (cursor == 0) { /* otherwise it may be bogus */
+ int col = ((ic >> 32) & 0x7fff) - 1;
+ if (col > cmdedit_prmt_len) {
+ cmdedit_x += (col - cmdedit_prmt_len);
+ while (cmdedit_x >= cmdedit_termw) {
+ cmdedit_x -= cmdedit_termw;
+ cmdedit_y++;
+ }
}
}
goto poll_again;
}
+#endif
#if ENABLE_FEATURE_ASSUME_UNICODE
{
@@ -2192,6 +2202,21 @@
#endif
} /* while (1) */
+#if ENABLE_FEATURE_EDITING_ASK_TERMINAL
+ if (S.sent_ESC_br_n6) {
+ /* "sleep 1; busybox ash" + hold [Enter] to trigger.
+ * We sent "ESC [ 6 n", but got '\n' first, and
+ * KEYCODE_CURSOR_POS response is now buffered from terminal.
+ * It's bad already and not much can be done with it
+ * (it _will_ be visible for the next process to read stdin),
+ * but without this delay it even shows up on the screen
+ * as garbage because we restore echo settings with tcsetattr
+ * before it comes in. UGLY!
+ */
+ usleep(20*1000);
+ }
+#endif
+
/* Stop bug catching using "command_must_not_be_used" trick */
#undef command