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 18 /* Known escape sequences for cursor and function keys. 19 * See "Xterm Control Sequences" 20 * http://invisible-island.net/xterm/ctlseqs/ctlseqs.html 21 * Array should be sorted from shortest to longest. 22 */ 23 static const char esccmds[] ALIGN1 = { 24 '\x7f' |0x80,KEYCODE_ALT_BACKSPACE, 25 '\b' |0x80,KEYCODE_ALT_BACKSPACE, 26 'd' |0x80,KEYCODE_ALT_D , 27 /* lineedit mimics bash: Alt-f and Alt-b are forward/backward 28 * word jumps. We cheat here and make them return ALT_LEFT/RIGHT 29 * keycodes. This way, lineedit need no special code to handle them. 30 * If we'll need to distinguish them, introduce new ALT_F/B keycodes, 31 * and update lineedit to react to them. 32 */ 33 'f' |0x80,KEYCODE_ALT_RIGHT, 34 'b' |0x80,KEYCODE_ALT_LEFT, 35 'O','A' |0x80,KEYCODE_UP , 36 'O','B' |0x80,KEYCODE_DOWN , 37 'O','C' |0x80,KEYCODE_RIGHT , 38 'O','D' |0x80,KEYCODE_LEFT , 39 'O','H' |0x80,KEYCODE_HOME , 40 'O','F' |0x80,KEYCODE_END , 41#if 0 42 'O','P' |0x80,KEYCODE_FUN1 , 43 /* [ESC] ESC O [2] P - [Alt-][Shift-]F1 */ 44 /* ESC [ O 1 ; 2 P - Shift-F1 */ 45 /* ESC [ O 1 ; 3 P - Alt-F1 */ 46 /* ESC [ O 1 ; 4 P - Alt-Shift-F1 */ 47 /* ESC [ O 1 ; 5 P - Ctrl-F1 */ 48 /* ESC [ O 1 ; 6 P - Ctrl-Shift-F1 */ 49 'O','Q' |0x80,KEYCODE_FUN2 , 50 'O','R' |0x80,KEYCODE_FUN3 , 51 'O','S' |0x80,KEYCODE_FUN4 , 52#endif 53 '[','A' |0x80,KEYCODE_UP , 54 '[','B' |0x80,KEYCODE_DOWN , 55 '[','C' |0x80,KEYCODE_RIGHT , 56 '[','D' |0x80,KEYCODE_LEFT , 57 /* ESC [ 1 ; 2 x, where x = A/B/C/D: Shift-<arrow> */ 58 /* ESC [ 1 ; 3 x, where x = A/B/C/D: Alt-<arrow> - implemented below */ 59 /* ESC [ 1 ; 4 x, where x = A/B/C/D: Alt-Shift-<arrow> */ 60 /* ESC [ 1 ; 5 x, where x = A/B/C/D: Ctrl-<arrow> - implemented below */ 61 /* ESC [ 1 ; 6 x, where x = A/B/C/D: Ctrl-Shift-<arrow> */ 62 /* ESC [ 1 ; 7 x, where x = A/B/C/D: Ctrl-Alt-<arrow> */ 63 /* ESC [ 1 ; 8 x, where x = A/B/C/D: Ctrl-Alt-Shift-<arrow> */ 64 '[','H' |0x80,KEYCODE_HOME , /* xterm */ 65 '[','F' |0x80,KEYCODE_END , /* xterm */ 66 /* [ESC] ESC [ [2] H - [Alt-][Shift-]Home (End similarly?) */ 67 /* '[','Z' |0x80,KEYCODE_SHIFT_TAB, */ 68 '[','1','~' |0x80,KEYCODE_HOME , /* vt100? linux vt? or what? */ 69 '[','2','~' |0x80,KEYCODE_INSERT , 70 /* ESC [ 2 ; 3 ~ - Alt-Insert */ 71 '[','3','~' |0x80,KEYCODE_DELETE , 72 /* [ESC] ESC [ 3 [;2] ~ - [Alt-][Shift-]Delete */ 73 /* ESC [ 3 ; 3 ~ - Alt-Delete */ 74 /* ESC [ 3 ; 5 ~ - Ctrl-Delete */ 75 '[','4','~' |0x80,KEYCODE_END , /* vt100? linux vt? or what? */ 76 '[','5','~' |0x80,KEYCODE_PAGEUP , 77 /* ESC [ 5 ; 3 ~ - Alt-PgUp */ 78 /* ESC [ 5 ; 5 ~ - Ctrl-PgUp */ 79 /* ESC [ 5 ; 7 ~ - Ctrl-Alt-PgUp */ 80 '[','6','~' |0x80,KEYCODE_PAGEDOWN, 81 '[','7','~' |0x80,KEYCODE_HOME , /* vt100? linux vt? or what? */ 82 '[','8','~' |0x80,KEYCODE_END , /* vt100? linux vt? or what? */ 83#if 0 84 '[','1','1','~'|0x80,KEYCODE_FUN1 , /* old xterm, deprecated by ESC O P */ 85 '[','1','2','~'|0x80,KEYCODE_FUN2 , /* old xterm... */ 86 '[','1','3','~'|0x80,KEYCODE_FUN3 , /* old xterm... */ 87 '[','1','4','~'|0x80,KEYCODE_FUN4 , /* old xterm... */ 88 '[','1','5','~'|0x80,KEYCODE_FUN5 , 89 /* [ESC] ESC [ 1 5 [;2] ~ - [Alt-][Shift-]F5 */ 90 '[','1','7','~'|0x80,KEYCODE_FUN6 , 91 '[','1','8','~'|0x80,KEYCODE_FUN7 , 92 '[','1','9','~'|0x80,KEYCODE_FUN8 , 93 '[','2','0','~'|0x80,KEYCODE_FUN9 , 94 '[','2','1','~'|0x80,KEYCODE_FUN10 , 95 '[','2','3','~'|0x80,KEYCODE_FUN11 , 96 '[','2','4','~'|0x80,KEYCODE_FUN12 , 97 /* ESC [ 2 4 ; 2 ~ - Shift-F12 */ 98 /* ESC [ 2 4 ; 3 ~ - Alt-F12 */ 99 /* ESC [ 2 4 ; 4 ~ - Alt-Shift-F12 */ 100 /* ESC [ 2 4 ; 5 ~ - Ctrl-F12 */ 101 /* ESC [ 2 4 ; 6 ~ - Ctrl-Shift-F12 */ 102#endif 103 /* '[','1',';','5','A' |0x80,KEYCODE_CTRL_UP , - unused */ 104 /* '[','1',';','5','B' |0x80,KEYCODE_CTRL_DOWN , - unused */ 105 '[','1',';','5','C' |0x80,KEYCODE_CTRL_RIGHT, 106 '[','1',';','5','D' |0x80,KEYCODE_CTRL_LEFT , 107 /* '[','1',';','3','A' |0x80,KEYCODE_ALT_UP , - unused */ 108 /* '[','1',';','3','B' |0x80,KEYCODE_ALT_DOWN , - unused */ 109 '[','1',';','3','C' |0x80,KEYCODE_ALT_RIGHT, 110 '[','1',';','3','D' |0x80,KEYCODE_ALT_LEFT , 111 /* '[','3',';','3','~' |0x80,KEYCODE_ALT_DELETE, - unused */ 112 0 113 }; 114 115 pfd.fd = fd; 116 pfd.events = POLLIN; 117 118 buffer++; /* saved chars counter is in buffer[-1] now */ 119 120 start_over: 121 errno = 0; 122 n = (unsigned char)buffer[-1]; 123 if (n == 0) { 124 /* If no data, wait for input. 125 * If requested, wait TIMEOUT ms. TIMEOUT = -1 is useful 126 * if fd can be in non-blocking mode. 127 */ 128 if (timeout >= -1) { 129 if (safe_poll(&pfd, 1, timeout) == 0) { 130 /* Timed out */ 131 errno = EAGAIN; 132 return -1; 133 } 134 } 135 /* It is tempting to read more than one byte here, 136 * but it breaks pasting. Example: at shell prompt, 137 * user presses "c","a","t" and then pastes "\nline\n". 138 * When we were reading 3 bytes here, we were eating 139 * "li" too, and cat was getting wrong input. 140 */ 141 n = safe_read(fd, buffer, 1); 142 if (n <= 0) 143 return -1; 144 } 145 146 { 147 unsigned char c = buffer[0]; 148 n--; 149 if (n) 150 memmove(buffer, buffer + 1, n); 151 /* Only ESC starts ESC sequences */ 152 if (c != 27) { 153 buffer[-1] = n; 154 return c; 155 } 156 } 157 158 /* Loop through known ESC sequences */ 159 seq = esccmds; 160 while (*seq != '\0') { 161 /* n - position in sequence we did not read yet */ 162 int i = 0; /* position in sequence to compare */ 163 164 /* Loop through chars in this sequence */ 165 while (1) { 166 /* So far escape sequence matched up to [i-1] */ 167 if (n <= i) { 168 /* Need more chars, read another one if it wouldn't block. 169 * Note that escape sequences come in as a unit, 170 * so if we block for long it's not really an escape sequence. 171 * Timeout is needed to reconnect escape sequences 172 * split up by transmission over a serial console. */ 173 if (safe_poll(&pfd, 1, 50) == 0) { 174 /* No more data! 175 * Array is sorted from shortest to longest, 176 * we can't match anything later in array - 177 * anything later is longer than this seq. 178 * Break out of both loops. */ 179 goto got_all; 180 } 181 errno = 0; 182 if (safe_read(fd, buffer + n, 1) <= 0) { 183 /* If EAGAIN, then fd is O_NONBLOCK and poll lied: 184 * in fact, there is no data. */ 185 if (errno != EAGAIN) { 186 /* otherwise: it's EOF/error */ 187 buffer[-1] = 0; 188 return -1; 189 } 190 goto got_all; 191 } 192 n++; 193 } 194 if (buffer[i] != (seq[i] & 0x7f)) { 195 /* This seq doesn't match, go to next */ 196 seq += i; 197 /* Forward to last char */ 198 while (!(*seq & 0x80)) 199 seq++; 200 /* Skip it and the keycode which follows */ 201 seq += 2; 202 break; 203 } 204 if (seq[i] & 0x80) { 205 /* Entire seq matched */ 206 n = 0; 207 /* n -= i; memmove(...); 208 * would be more correct, 209 * but we never read ahead that much, 210 * and n == i here. */ 211 buffer[-1] = 0; 212 return (signed char)seq[i+1]; 213 } 214 i++; 215 } 216 } 217 /* We did not find matching sequence. 218 * We possibly read and stored more input in buffer[] by now. 219 * n = bytes read. Try to read more until we time out. 220 */ 221 while (n < KEYCODE_BUFFER_SIZE-1) { /* 1 for count byte at buffer[-1] */ 222 if (safe_poll(&pfd, 1, 50) == 0) { 223 /* No more data! */ 224 break; 225 } 226 errno = 0; 227 if (safe_read(fd, buffer + n, 1) <= 0) { 228 /* If EAGAIN, then fd is O_NONBLOCK and poll lied: 229 * in fact, there is no data. */ 230 if (errno != EAGAIN) { 231 /* otherwise: it's EOF/error */ 232 buffer[-1] = 0; 233 return -1; 234 } 235 break; 236 } 237 n++; 238 /* Try to decipher "ESC [ NNN ; NNN R" sequence */ 239 if ((ENABLE_FEATURE_EDITING_ASK_TERMINAL 240 || ENABLE_FEATURE_VI_ASK_TERMINAL 241 || ENABLE_FEATURE_LESS_ASK_TERMINAL 242 ) 243 && n >= 5 244 && buffer[0] == '[' 245 && buffer[n-1] == 'R' 246 && isdigit(buffer[1]) 247 ) { 248 char *end; 249 unsigned long row, col; 250 251 row = strtoul(buffer + 1, &end, 10); 252 if (*end != ';' || !isdigit(end[1])) 253 continue; 254 col = strtoul(end + 1, &end, 10); 255 if (*end != 'R') 256 continue; 257 if (row < 1 || col < 1 || (row | col) > 0x7fff) 258 continue; 259 260 buffer[-1] = 0; 261 /* Pack into "1 <row15bits> <col16bits>" 32-bit sequence */ 262 col |= (((-1 << 15) | row) << 16); 263 /* Return it in high-order word */ 264 return ((int64_t) col << 32) | (uint32_t)KEYCODE_CURSOR_POS; 265 } 266 } 267 got_all: 268 269 if (n <= 1) { 270 /* Alt-x is usually returned as ESC x. 271 * Report ESC, x is remembered for the next call. 272 */ 273 buffer[-1] = n; 274 return 27; 275 } 276 277 /* We were doing "buffer[-1] = n; return c;" here, but this results 278 * in unknown key sequences being interpreted as ESC + garbage. 279 * This was not useful. Pretend there was no key pressed, 280 * go and wait for a new keypress: 281 */ 282 buffer[-1] = 0; 283 goto start_over; 284} 285 286void FAST_FUNC read_key_ungets(char *buffer, const char *str, unsigned len) 287{ 288 unsigned cur_len = (unsigned char)buffer[0]; 289 if (len > KEYCODE_BUFFER_SIZE-1 - cur_len) 290 len = KEYCODE_BUFFER_SIZE-1 - cur_len; 291 memcpy(buffer + 1 + cur_len, str, len); 292 buffer[0] += len; 293} 294