source: MondoRescue/branches/3.2/mindi-busybox/libbb/read_key.c@ 3232

Last change on this file since 3232 was 3232, checked in by Bruno Cornec, 10 years ago
  • Update mindi-busybox to 1.21.1
  • Property svn:eol-style set to native
File size: 8.6 KB
RevLine 
[2725]1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) 2008 Rob Landley <rob@landley.net>
6 * Copyright (C) 2008 Denys Vlasenko <vda.linux@googlemail.com>
7 *
8 * Licensed under GPLv2, see file LICENSE in this source tree.
9 */
10#include "libbb.h"
11
12int64_t FAST_FUNC read_key(int fd, char *buffer, int timeout)
13{
14 struct pollfd pfd;
15 const char *seq;
16 int n;
17
[3232]18 /* Known escape sequences for cursor and function keys.
19 * See "Xterm Control Sequences"
20 * http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
21 */
[2725]22 static const char esccmds[] ALIGN1 = {
23 'O','A' |0x80,KEYCODE_UP ,
24 'O','B' |0x80,KEYCODE_DOWN ,
25 'O','C' |0x80,KEYCODE_RIGHT ,
26 'O','D' |0x80,KEYCODE_LEFT ,
27 'O','H' |0x80,KEYCODE_HOME ,
28 'O','F' |0x80,KEYCODE_END ,
29#if 0
30 'O','P' |0x80,KEYCODE_FUN1 ,
31 /* [ESC] ESC O [2] P - [Alt-][Shift-]F1 */
32 /* ESC [ O 1 ; 2 P - Shift-F1 */
33 /* ESC [ O 1 ; 3 P - Alt-F1 */
34 /* ESC [ O 1 ; 4 P - Alt-Shift-F1 */
35 /* ESC [ O 1 ; 5 P - Ctrl-F1 */
36 /* ESC [ O 1 ; 6 P - Ctrl-Shift-F1 */
37 'O','Q' |0x80,KEYCODE_FUN2 ,
38 'O','R' |0x80,KEYCODE_FUN3 ,
39 'O','S' |0x80,KEYCODE_FUN4 ,
40#endif
41 '[','A' |0x80,KEYCODE_UP ,
42 '[','B' |0x80,KEYCODE_DOWN ,
43 '[','C' |0x80,KEYCODE_RIGHT ,
44 '[','D' |0x80,KEYCODE_LEFT ,
45 /* ESC [ 1 ; 2 x, where x = A/B/C/D: Shift-<arrow> */
[3232]46 /* ESC [ 1 ; 3 x, where x = A/B/C/D: Alt-<arrow> - implemented below */
[2725]47 /* ESC [ 1 ; 4 x, where x = A/B/C/D: Alt-Shift-<arrow> */
48 /* ESC [ 1 ; 5 x, where x = A/B/C/D: Ctrl-<arrow> - implemented below */
49 /* ESC [ 1 ; 6 x, where x = A/B/C/D: Ctrl-Shift-<arrow> */
[3232]50 /* ESC [ 1 ; 7 x, where x = A/B/C/D: Ctrl-Alt-<arrow> */
51 /* ESC [ 1 ; 8 x, where x = A/B/C/D: Ctrl-Alt-Shift-<arrow> */
[2725]52 '[','H' |0x80,KEYCODE_HOME , /* xterm */
53 '[','F' |0x80,KEYCODE_END , /* xterm */
[3232]54 /* [ESC] ESC [ [2] H - [Alt-][Shift-]Home (End similarly?) */
55 /* '[','Z' |0x80,KEYCODE_SHIFT_TAB, */
[2725]56 '[','1','~' |0x80,KEYCODE_HOME , /* vt100? linux vt? or what? */
57 '[','2','~' |0x80,KEYCODE_INSERT ,
58 /* ESC [ 2 ; 3 ~ - Alt-Insert */
59 '[','3','~' |0x80,KEYCODE_DELETE ,
60 /* [ESC] ESC [ 3 [;2] ~ - [Alt-][Shift-]Delete */
61 /* ESC [ 3 ; 3 ~ - Alt-Delete */
62 /* ESC [ 3 ; 5 ~ - Ctrl-Delete */
63 '[','4','~' |0x80,KEYCODE_END , /* vt100? linux vt? or what? */
64 '[','5','~' |0x80,KEYCODE_PAGEUP ,
65 /* ESC [ 5 ; 3 ~ - Alt-PgUp */
66 /* ESC [ 5 ; 5 ~ - Ctrl-PgUp */
67 /* ESC [ 5 ; 7 ~ - Ctrl-Alt-PgUp */
68 '[','6','~' |0x80,KEYCODE_PAGEDOWN,
69 '[','7','~' |0x80,KEYCODE_HOME , /* vt100? linux vt? or what? */
70 '[','8','~' |0x80,KEYCODE_END , /* vt100? linux vt? or what? */
71#if 0
[3232]72 '[','1','1','~'|0x80,KEYCODE_FUN1 , /* old xterm, deprecated by ESC O P */
73 '[','1','2','~'|0x80,KEYCODE_FUN2 , /* old xterm... */
74 '[','1','3','~'|0x80,KEYCODE_FUN3 , /* old xterm... */
75 '[','1','4','~'|0x80,KEYCODE_FUN4 , /* old xterm... */
[2725]76 '[','1','5','~'|0x80,KEYCODE_FUN5 ,
77 /* [ESC] ESC [ 1 5 [;2] ~ - [Alt-][Shift-]F5 */
78 '[','1','7','~'|0x80,KEYCODE_FUN6 ,
79 '[','1','8','~'|0x80,KEYCODE_FUN7 ,
80 '[','1','9','~'|0x80,KEYCODE_FUN8 ,
81 '[','2','0','~'|0x80,KEYCODE_FUN9 ,
82 '[','2','1','~'|0x80,KEYCODE_FUN10 ,
83 '[','2','3','~'|0x80,KEYCODE_FUN11 ,
84 '[','2','4','~'|0x80,KEYCODE_FUN12 ,
85 /* ESC [ 2 4 ; 2 ~ - Shift-F12 */
86 /* ESC [ 2 4 ; 3 ~ - Alt-F12 */
87 /* ESC [ 2 4 ; 4 ~ - Alt-Shift-F12 */
88 /* ESC [ 2 4 ; 5 ~ - Ctrl-F12 */
89 /* ESC [ 2 4 ; 6 ~ - Ctrl-Shift-F12 */
90#endif
91 /* '[','1',';','5','A' |0x80,KEYCODE_CTRL_UP , - unused */
92 /* '[','1',';','5','B' |0x80,KEYCODE_CTRL_DOWN , - unused */
93 '[','1',';','5','C' |0x80,KEYCODE_CTRL_RIGHT,
94 '[','1',';','5','D' |0x80,KEYCODE_CTRL_LEFT ,
[3232]95 /* '[','1',';','3','A' |0x80,KEYCODE_ALT_UP , - unused */
96 /* '[','1',';','3','B' |0x80,KEYCODE_ALT_DOWN , - unused */
97 '[','1',';','3','C' |0x80,KEYCODE_ALT_RIGHT,
98 '[','1',';','3','D' |0x80,KEYCODE_ALT_LEFT ,
99 /* '[','3',';','3','~' |0x80,KEYCODE_ALT_DELETE, - unused */
[2725]100 0
101 };
102
103 pfd.fd = fd;
104 pfd.events = POLLIN;
105
106 buffer++; /* saved chars counter is in buffer[-1] now */
107
108 start_over:
109 errno = 0;
110 n = (unsigned char)buffer[-1];
111 if (n == 0) {
112 /* If no data, wait for input.
113 * If requested, wait TIMEOUT ms. TIMEOUT = -1 is useful
114 * if fd can be in non-blocking mode.
115 */
116 if (timeout >= -1) {
117 if (safe_poll(&pfd, 1, timeout) == 0) {
118 /* Timed out */
119 errno = EAGAIN;
120 return -1;
121 }
122 }
123 /* It is tempting to read more than one byte here,
124 * but it breaks pasting. Example: at shell prompt,
125 * user presses "c","a","t" and then pastes "\nline\n".
126 * When we were reading 3 bytes here, we were eating
127 * "li" too, and cat was getting wrong input.
128 */
129 n = safe_read(fd, buffer, 1);
130 if (n <= 0)
131 return -1;
132 }
133
134 {
135 unsigned char c = buffer[0];
136 n--;
137 if (n)
138 memmove(buffer, buffer + 1, n);
139 /* Only ESC starts ESC sequences */
140 if (c != 27) {
141 buffer[-1] = n;
142 return c;
143 }
144 }
145
146 /* Loop through known ESC sequences */
147 seq = esccmds;
148 while (*seq != '\0') {
149 /* n - position in sequence we did not read yet */
150 int i = 0; /* position in sequence to compare */
151
152 /* Loop through chars in this sequence */
153 while (1) {
154 /* So far escape sequence matched up to [i-1] */
155 if (n <= i) {
156 /* Need more chars, read another one if it wouldn't block.
157 * Note that escape sequences come in as a unit,
158 * so if we block for long it's not really an escape sequence.
159 * Timeout is needed to reconnect escape sequences
160 * split up by transmission over a serial console. */
161 if (safe_poll(&pfd, 1, 50) == 0) {
162 /* No more data!
163 * Array is sorted from shortest to longest,
164 * we can't match anything later in array -
165 * anything later is longer than this seq.
166 * Break out of both loops. */
167 goto got_all;
168 }
169 errno = 0;
170 if (safe_read(fd, buffer + n, 1) <= 0) {
171 /* If EAGAIN, then fd is O_NONBLOCK and poll lied:
172 * in fact, there is no data. */
173 if (errno != EAGAIN) {
174 /* otherwise: it's EOF/error */
175 buffer[-1] = 0;
176 return -1;
177 }
178 goto got_all;
179 }
180 n++;
181 }
182 if (buffer[i] != (seq[i] & 0x7f)) {
183 /* This seq doesn't match, go to next */
184 seq += i;
185 /* Forward to last char */
186 while (!(*seq & 0x80))
187 seq++;
188 /* Skip it and the keycode which follows */
189 seq += 2;
190 break;
191 }
192 if (seq[i] & 0x80) {
193 /* Entire seq matched */
194 n = 0;
195 /* n -= i; memmove(...);
196 * would be more correct,
197 * but we never read ahead that much,
198 * and n == i here. */
199 buffer[-1] = 0;
200 return (signed char)seq[i+1];
201 }
202 i++;
203 }
204 }
205 /* We did not find matching sequence.
206 * We possibly read and stored more input in buffer[] by now.
207 * n = bytes read. Try to read more until we time out.
208 */
209 while (n < KEYCODE_BUFFER_SIZE-1) { /* 1 for count byte at buffer[-1] */
210 if (safe_poll(&pfd, 1, 50) == 0) {
211 /* No more data! */
212 break;
213 }
214 errno = 0;
215 if (safe_read(fd, buffer + n, 1) <= 0) {
216 /* If EAGAIN, then fd is O_NONBLOCK and poll lied:
217 * in fact, there is no data. */
218 if (errno != EAGAIN) {
219 /* otherwise: it's EOF/error */
220 buffer[-1] = 0;
221 return -1;
222 }
223 break;
224 }
225 n++;
226 /* Try to decipher "ESC [ NNN ; NNN R" sequence */
[3232]227 if ((ENABLE_FEATURE_EDITING_ASK_TERMINAL
228 || ENABLE_FEATURE_VI_ASK_TERMINAL
229 || ENABLE_FEATURE_LESS_ASK_TERMINAL
230 )
[2725]231 && n >= 5
232 && buffer[0] == '['
233 && buffer[n-1] == 'R'
234 && isdigit(buffer[1])
235 ) {
236 char *end;
237 unsigned long row, col;
238
239 row = strtoul(buffer + 1, &end, 10);
240 if (*end != ';' || !isdigit(end[1]))
241 continue;
242 col = strtoul(end + 1, &end, 10);
243 if (*end != 'R')
244 continue;
245 if (row < 1 || col < 1 || (row | col) > 0x7fff)
246 continue;
247
248 buffer[-1] = 0;
249 /* Pack into "1 <row15bits> <col16bits>" 32-bit sequence */
250 col |= (((-1 << 15) | row) << 16);
251 /* Return it in high-order word */
252 return ((int64_t) col << 32) | (uint32_t)KEYCODE_CURSOR_POS;
253 }
254 }
255 got_all:
256
257 if (n <= 1) {
258 /* Alt-x is usually returned as ESC x.
259 * Report ESC, x is remembered for the next call.
260 */
261 buffer[-1] = n;
262 return 27;
263 }
264
265 /* We were doing "buffer[-1] = n; return c;" here, but this results
266 * in unknown key sequences being interpreted as ESC + garbage.
267 * This was not useful. Pretend there was no key pressed,
268 * go and wait for a new keypress:
269 */
270 buffer[-1] = 0;
271 goto start_over;
272}
273
274void FAST_FUNC read_key_ungets(char *buffer, const char *str, unsigned len)
275{
276 unsigned cur_len = (unsigned char)buffer[0];
277 if (len > KEYCODE_BUFFER_SIZE-1 - cur_len)
278 len = KEYCODE_BUFFER_SIZE-1 - cur_len;
279 memcpy(buffer + 1 + cur_len, str, len);
280 buffer[0] += len;
281}
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