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-rw-r--r--miscutils/less.c137
1 files changed, 53 insertions, 84 deletions
diff --git a/miscutils/less.c b/miscutils/less.c
index f367b0ebc..d9ada619a 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -36,34 +36,9 @@
/* The escape code to clear to end of line */
#define CLEAR_2_EOL "\033[K"
-/* These are the escape sequences corresponding to special keys */
enum {
- REAL_KEY_UP = 'A',
- REAL_KEY_DOWN = 'B',
- REAL_KEY_RIGHT = 'C',
- REAL_KEY_LEFT = 'D',
- REAL_PAGE_UP = '5',
- REAL_PAGE_DOWN = '6',
- REAL_KEY_HOME = '7', // vt100? linux vt? or what?
- REAL_KEY_END = '8',
- REAL_KEY_HOME_ALT = '1', // ESC [1~ (vt100? linux vt? or what?)
- REAL_KEY_END_ALT = '4', // ESC [4~
- REAL_KEY_HOME_XTERM = 'H',
- REAL_KEY_END_XTERM = 'F',
-
-/* These are the special codes assigned by this program to the special keys */
- KEY_UP = 20,
- KEY_DOWN = 21,
- KEY_RIGHT = 22,
- KEY_LEFT = 23,
- PAGE_UP = 24,
- PAGE_DOWN = 25,
- KEY_HOME = 26,
- KEY_END = 27,
-
/* Absolute max of lines eaten */
MAXLINES = CONFIG_FEATURE_LESS_MAXLINES,
-
/* This many "after the end" lines we will show (at max) */
TILDES = 1,
};
@@ -133,6 +108,8 @@ struct globals {
#define max_displayed_line (G.max_displayed_line)
#define width (G.width )
#define winch_counter (G.winch_counter )
+/* This one is 100% not cached by compiler on read access */
+#define WINCH_COUNTER (*(volatile unsigned *)&winch_counter)
#define eof_error (G.eof_error )
#define readpos (G.readpos )
#define readeof (G.readeof )
@@ -824,9 +801,10 @@ static void reinitialize(void)
buffer_fill_and_print();
}
-static ssize_t getch_nowait(char* input, int sz)
+static ssize_t getch_nowait(void)
{
- ssize_t rd;
+ char input[KEYCODE_BUFFER_SIZE];
+ int rd;
struct pollfd pfd[2];
pfd[0].fd = STDIN_FILENO;
@@ -842,34 +820,39 @@ static ssize_t getch_nowait(char* input, int sz)
* (switch fd into O_NONBLOCK'ed mode to avoid it)
*/
rd = 1;
- if (max_fline <= cur_fline + max_displayed_line
- && eof_error > 0 /* did NOT reach eof yet */
+ /* Are we interested in stdin? */
+//TODO: reuse code for determining this
+ if (!(option_mask32 & FLAG_S)
+ ? !(max_fline > cur_fline + max_displayed_line)
+ : !(max_fline >= cur_fline
+ && max_lineno > LINENO(flines[cur_fline]) + max_displayed_line)
) {
- /* We are interested in stdin */
- rd = 0;
+ if (eof_error > 0) /* did NOT reach eof yet */
+ rd = 0; /* yes, we are interested in stdin */
}
- /* position cursor if line input is done */
+ /* Position cursor if line input is done */
if (less_gets_pos >= 0)
move_cursor(max_displayed_line + 2, less_gets_pos + 1);
fflush(stdout);
#if ENABLE_FEATURE_LESS_WINCH
while (1) {
int r;
+ /* NB: SIGWINCH interrupts poll() */
r = poll(pfd + rd, 2 - rd, -1);
- if (/*r < 0 && errno == EINTR &&*/ winch_counter) {
- input[0] = '\\'; /* anything which has no defined function */
- return 1;
- }
+ if (/*r < 0 && errno == EINTR &&*/ winch_counter)
+ return '\\'; /* anything which has no defined function */
if (r) break;
}
#else
safe_poll(pfd + rd, 2 - rd, -1);
#endif
- input[0] = '\0';
- rd = safe_read(kbd_fd, input, sz); /* NB: kbd_fd is in O_NONBLOCK mode */
- if (rd < 0 && errno == EAGAIN) {
- /* No keyboard input -> we have input on stdin! */
+ /* We have kbd_fd in O_NONBLOCK mode, read inside read_key()
+ * would not block even if there is no input available */
+ rd = read_key(kbd_fd, NULL, input);
+ if (rd == -1 && errno == EAGAIN) {
+ /* No keyboard input available. Since poll() did return,
+ * we should have input on stdin */
read_lines();
buffer_fill_and_print();
goto again;
@@ -883,51 +866,29 @@ static ssize_t getch_nowait(char* input, int sz)
* special return codes. Note that this function works best with raw input. */
static int less_getch(int pos)
{
- unsigned char input[16];
- unsigned i;
+ int i;
again:
less_gets_pos = pos;
- memset(input, 0, sizeof(input));
- getch_nowait((char *)input, sizeof(input));
+ i = getch_nowait();
less_gets_pos = -1;
- /* Detect escape sequences (i.e. arrow keys) and handle
- * them accordingly */
- if (input[0] == '\033' && input[1] == '[') {
- i = input[2] - REAL_KEY_UP;
- if (i < 4)
- return 20 + i;
- i = input[2] - REAL_PAGE_UP;
- if (i < 4)
- return 24 + i;
- if (input[2] == REAL_KEY_HOME_XTERM)
- return KEY_HOME;
- if (input[2] == REAL_KEY_HOME_ALT)
- return KEY_HOME;
- if (input[2] == REAL_KEY_END_XTERM)
- return KEY_END;
- if (input[2] == REAL_KEY_END_ALT)
- return KEY_END;
- return 0;
- }
- /* Reject almost all control chars */
- i = input[0];
- if (i < ' ' && i != 0x0d && i != 8)
+ /* Discard Ctrl-something chars */
+ if (i >= 0 && i < ' ' && i != 0x0d && i != 8)
goto again;
return i;
}
static char* less_gets(int sz)
{
- char c;
+ int c;
unsigned i = 0;
char *result = xzalloc(1);
while (1) {
c = '\0';
less_gets_pos = sz + i;
- getch_nowait(&c, 1);
+ c = getch_nowait();
if (c == 0x0d) {
result[i] = '\0';
less_gets_pos = -1;
@@ -939,7 +900,7 @@ static char* less_gets(int sz)
printf("\x8 \x8");
i--;
}
- if (c < ' ')
+ if (c < ' ') /* filters out KEYCODE_xxx too (<0) */
continue;
if (i >= width - sz - 1)
continue; /* len limit */
@@ -1151,8 +1112,8 @@ static void number_process(int first_digit)
{
unsigned i;
int num;
+ int keypress;
char num_input[sizeof(int)*4]; /* more than enough */
- char keypress;
num_input[0] = first_digit;
@@ -1163,15 +1124,14 @@ static void number_process(int first_digit)
/* Receive input until a letter is given */
i = 1;
while (i < sizeof(num_input)-1) {
- num_input[i] = less_getch(i + 1);
- if (!num_input[i] || !isdigit(num_input[i]))
+ keypress = less_getch(i + 1);
+ if ((unsigned)keypress > 255 || !isdigit(num_input[i]))
break;
- bb_putchar(num_input[i]);
+ num_input[i] = keypress;
+ bb_putchar(keypress);
i++;
}
- /* Take the final letter out of the digits string */
- keypress = num_input[i];
num_input[i] = '\0';
num = bb_strtou(num_input, NULL, 10);
/* on format error, num == -1 */
@@ -1182,10 +1142,10 @@ static void number_process(int first_digit)
/* We now know the number and the letter entered, so we process them */
switch (keypress) {
- case KEY_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
+ case KEYCODE_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
buffer_down(num);
break;
- case KEY_UP: case 'b': case 'w': case 'y': case 'u':
+ case KEYCODE_UP: case 'b': case 'w': case 'y': case 'u':
buffer_up(num);
break;
case 'g': case '<': case 'G': case '>':
@@ -1413,16 +1373,16 @@ static void match_left_bracket(char bracket)
static void keypress_process(int keypress)
{
switch (keypress) {
- case KEY_DOWN: case 'e': case 'j': case 0x0d:
+ case KEYCODE_DOWN: case 'e': case 'j': case 0x0d:
buffer_down(1);
break;
- case KEY_UP: case 'y': case 'k':
+ case KEYCODE_UP: case 'y': case 'k':
buffer_up(1);
break;
- case PAGE_DOWN: case ' ': case 'z': case 'f':
+ case KEYCODE_PAGEDOWN: case ' ': case 'z': case 'f':
buffer_down(max_displayed_line + 1);
break;
- case PAGE_UP: case 'w': case 'b':
+ case KEYCODE_PAGEUP: case 'w': case 'b':
buffer_up(max_displayed_line + 1);
break;
case 'd':
@@ -1431,10 +1391,10 @@ static void keypress_process(int keypress)
case 'u':
buffer_up((max_displayed_line + 1) / 2);
break;
- case KEY_HOME: case 'g': case 'p': case '<': case '%':
+ case KEYCODE_HOME: case 'g': case 'p': case '<': case '%':
buffer_line(0);
break;
- case KEY_END: case 'G': case '>':
+ case KEYCODE_END: case 'G': case '>':
cur_fline = MAXLINES;
read_lines();
buffer_line(cur_fline);
@@ -1586,7 +1546,8 @@ int less_main(int argc, char **argv)
reinitialize();
while (1) {
#if ENABLE_FEATURE_LESS_WINCH
- if (winch_counter) {
+ while (WINCH_COUNTER) {
+ again:
winch_counter--;
get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
/* 20: two tabstops + 4 */
@@ -1597,8 +1558,16 @@ int less_main(int argc, char **argv)
max_displayed_line -= 2;
free(buffer);
buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
+ /* Avoid re-wrap and/or redraw if we already know
+ * we need to do it again. These ops are expensive */
+ if (WINCH_COUNTER)
+ goto again;
re_wrap();
+ if (WINCH_COUNTER)
+ goto again;
buffer_fill_and_print();
+ /* This took some time. Loop back and check,
+ * were there another SIGWINCH? */
}
#endif
keypress = less_getch(-1); /* -1: do not position cursor */
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