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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 2008 Rob Landley <rob@landley.net>
* Copyright (C) 2008 Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
int64_t FAST_FUNC read_key(int fd, char *buffer, int timeout)
{
struct pollfd pfd;
const char *seq;
int n;
/* Known escape sequences for cursor and function keys */
static const char esccmds[] ALIGN1 = {
'O','A' |0x80,KEYCODE_UP ,
'O','B' |0x80,KEYCODE_DOWN ,
'O','C' |0x80,KEYCODE_RIGHT ,
'O','D' |0x80,KEYCODE_LEFT ,
'O','H' |0x80,KEYCODE_HOME ,
'O','F' |0x80,KEYCODE_END ,
#if 0
'O','P' |0x80,KEYCODE_FUN1 ,
/* [ESC] ESC O [2] P - [Alt-][Shift-]F1 */
/* ESC [ O 1 ; 2 P - Shift-F1 */
/* ESC [ O 1 ; 3 P - Alt-F1 */
/* ESC [ O 1 ; 4 P - Alt-Shift-F1 */
/* ESC [ O 1 ; 5 P - Ctrl-F1 */
/* ESC [ O 1 ; 6 P - Ctrl-Shift-F1 */
'O','Q' |0x80,KEYCODE_FUN2 ,
'O','R' |0x80,KEYCODE_FUN3 ,
'O','S' |0x80,KEYCODE_FUN4 ,
#endif
'[','A' |0x80,KEYCODE_UP ,
'[','B' |0x80,KEYCODE_DOWN ,
'[','C' |0x80,KEYCODE_RIGHT ,
'[','D' |0x80,KEYCODE_LEFT ,
/* ESC [ 1 ; 2 x, where x = A/B/C/D: Shift-<arrow> */
/* ESC [ 1 ; 3 x, where x = A/B/C/D: Alt-<arrow> */
/* ESC [ 1 ; 4 x, where x = A/B/C/D: Alt-Shift-<arrow> */
/* ESC [ 1 ; 5 x, where x = A/B/C/D: Ctrl-<arrow> - implemented below */
/* ESC [ 1 ; 6 x, where x = A/B/C/D: Ctrl-Shift-<arrow> */
'[','H' |0x80,KEYCODE_HOME , /* xterm */
/* [ESC] ESC [ [2] H - [Alt-][Shift-]Home */
'[','F' |0x80,KEYCODE_END , /* xterm */
'[','1','~' |0x80,KEYCODE_HOME , /* vt100? linux vt? or what? */
'[','2','~' |0x80,KEYCODE_INSERT ,
/* ESC [ 2 ; 3 ~ - Alt-Insert */
'[','3','~' |0x80,KEYCODE_DELETE ,
/* [ESC] ESC [ 3 [;2] ~ - [Alt-][Shift-]Delete */
/* ESC [ 3 ; 3 ~ - Alt-Delete */
/* ESC [ 3 ; 5 ~ - Ctrl-Delete */
'[','4','~' |0x80,KEYCODE_END , /* vt100? linux vt? or what? */
'[','5','~' |0x80,KEYCODE_PAGEUP ,
/* ESC [ 5 ; 3 ~ - Alt-PgUp */
/* ESC [ 5 ; 5 ~ - Ctrl-PgUp */
/* ESC [ 5 ; 7 ~ - Ctrl-Alt-PgUp */
'[','6','~' |0x80,KEYCODE_PAGEDOWN,
'[','7','~' |0x80,KEYCODE_HOME , /* vt100? linux vt? or what? */
'[','8','~' |0x80,KEYCODE_END , /* vt100? linux vt? or what? */
#if 0
'[','1','1','~'|0x80,KEYCODE_FUN1 ,
'[','1','2','~'|0x80,KEYCODE_FUN2 ,
'[','1','3','~'|0x80,KEYCODE_FUN3 ,
'[','1','4','~'|0x80,KEYCODE_FUN4 ,
'[','1','5','~'|0x80,KEYCODE_FUN5 ,
/* [ESC] ESC [ 1 5 [;2] ~ - [Alt-][Shift-]F5 */
'[','1','7','~'|0x80,KEYCODE_FUN6 ,
'[','1','8','~'|0x80,KEYCODE_FUN7 ,
'[','1','9','~'|0x80,KEYCODE_FUN8 ,
'[','2','0','~'|0x80,KEYCODE_FUN9 ,
'[','2','1','~'|0x80,KEYCODE_FUN10 ,
'[','2','3','~'|0x80,KEYCODE_FUN11 ,
'[','2','4','~'|0x80,KEYCODE_FUN12 ,
/* ESC [ 2 4 ; 2 ~ - Shift-F12 */
/* ESC [ 2 4 ; 3 ~ - Alt-F12 */
/* ESC [ 2 4 ; 4 ~ - Alt-Shift-F12 */
/* ESC [ 2 4 ; 5 ~ - Ctrl-F12 */
/* ESC [ 2 4 ; 6 ~ - Ctrl-Shift-F12 */
#endif
/* '[','1',';','5','A' |0x80,KEYCODE_CTRL_UP , - unused */
/* '[','1',';','5','B' |0x80,KEYCODE_CTRL_DOWN , - unused */
'[','1',';','5','C' |0x80,KEYCODE_CTRL_RIGHT,
'[','1',';','5','D' |0x80,KEYCODE_CTRL_LEFT ,
0
/* ESC [ Z - Shift-Tab */
};
pfd.fd = fd;
pfd.events = POLLIN;
buffer++; /* saved chars counter is in buffer[-1] now */
start_over:
errno = 0;
n = (unsigned char)buffer[-1];
if (n == 0) {
/* If no data, wait for input.
* If requested, wait TIMEOUT ms. TIMEOUT = -1 is useful
* if fd can be in non-blocking mode.
*/
if (timeout >= -1) {
if (safe_poll(&pfd, 1, timeout) == 0) {
/* Timed out */
errno = EAGAIN;
return -1;
}
}
/* It is tempting to read more than one byte here,
* but it breaks pasting. Example: at shell prompt,
* user presses "c","a","t" and then pastes "\nline\n".
* When we were reading 3 bytes here, we were eating
* "li" too, and cat was getting wrong input.
*/
n = safe_read(fd, buffer, 1);
if (n <= 0)
return -1;
}
{
unsigned char c = buffer[0];
n--;
if (n)
memmove(buffer, buffer + 1, n);
/* Only ESC starts ESC sequences */
if (c != 27) {
buffer[-1] = n;
return c;
}
}
/* Loop through known ESC sequences */
seq = esccmds;
while (*seq != '\0') {
/* n - position in sequence we did not read yet */
int i = 0; /* position in sequence to compare */
/* Loop through chars in this sequence */
while (1) {
/* So far escape sequence matched up to [i-1] */
if (n <= i) {
/* Need more chars, read another one if it wouldn't block.
* Note that escape sequences come in as a unit,
* so if we block for long it's not really an escape sequence.
* Timeout is needed to reconnect escape sequences
* split up by transmission over a serial console. */
if (safe_poll(&pfd, 1, 50) == 0) {
/* No more data!
* Array is sorted from shortest to longest,
* we can't match anything later in array -
* anything later is longer than this seq.
* Break out of both loops. */
goto got_all;
}
errno = 0;
if (safe_read(fd, buffer + n, 1) <= 0) {
/* If EAGAIN, then fd is O_NONBLOCK and poll lied:
* in fact, there is no data. */
if (errno != EAGAIN) {
/* otherwise: it's EOF/error */
buffer[-1] = 0;
return -1;
}
goto got_all;
}
n++;
}
if (buffer[i] != (seq[i] & 0x7f)) {
/* This seq doesn't match, go to next */
seq += i;
/* Forward to last char */
while (!(*seq & 0x80))
seq++;
/* Skip it and the keycode which follows */
seq += 2;
break;
}
if (seq[i] & 0x80) {
/* Entire seq matched */
n = 0;
/* n -= i; memmove(...);
* would be more correct,
* but we never read ahead that much,
* and n == i here. */
buffer[-1] = 0;
return (signed char)seq[i+1];
}
i++;
}
}
/* We did not find matching sequence.
* We possibly read and stored more input in buffer[] by now.
* n = bytes read. Try to read more until we time out.
*/
while (n < KEYCODE_BUFFER_SIZE-1) { /* 1 for count byte at buffer[-1] */
if (safe_poll(&pfd, 1, 50) == 0) {
/* No more data! */
break;
}
errno = 0;
if (safe_read(fd, buffer + n, 1) <= 0) {
/* If EAGAIN, then fd is O_NONBLOCK and poll lied:
* in fact, there is no data. */
if (errno != EAGAIN) {
/* otherwise: it's EOF/error */
buffer[-1] = 0;
return -1;
}
break;
}
n++;
/* Try to decipher "ESC [ NNN ; NNN R" sequence */
if (ENABLE_FEATURE_EDITING_ASK_TERMINAL
&& n >= 5
&& buffer[0] == '['
&& buffer[n-1] == 'R'
&& isdigit(buffer[1])
) {
char *end;
unsigned long row, col;
row = strtoul(buffer + 1, &end, 10);
if (*end != ';' || !isdigit(end[1]))
continue;
col = strtoul(end + 1, &end, 10);
if (*end != 'R')
continue;
if (row < 1 || col < 1 || (row | col) > 0x7fff)
continue;
buffer[-1] = 0;
/* Pack into "1 <row15bits> <col16bits>" 32-bit sequence */
col |= (((-1 << 15) | row) << 16);
/* Return it in high-order word */
return ((int64_t) col << 32) | (uint32_t)KEYCODE_CURSOR_POS;
}
}
got_all:
if (n <= 1) {
/* Alt-x is usually returned as ESC x.
* Report ESC, x is remembered for the next call.
*/
buffer[-1] = n;
return 27;
}
/* We were doing "buffer[-1] = n; return c;" here, but this results
* in unknown key sequences being interpreted as ESC + garbage.
* This was not useful. Pretend there was no key pressed,
* go and wait for a new keypress:
*/
buffer[-1] = 0;
goto start_over;
}
void FAST_FUNC read_key_ungets(char *buffer, const char *str, unsigned len)
{
unsigned cur_len = (unsigned char)buffer[0];
if (len > KEYCODE_BUFFER_SIZE-1 - cur_len)
len = KEYCODE_BUFFER_SIZE-1 - cur_len;
memcpy(buffer + 1 + cur_len, str, len);
buffer[0] += len;
}
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