/* 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 GPLv2, see file LICENSE in this source tree. */ #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. * See "Xterm Control Sequences" * http://invisible-island.net/xterm/ctlseqs/ctlseqs.html */ 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> - implemented below */ /* 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> */ /* ESC [ 1 ; 7 x, where x = A/B/C/D: Ctrl-Alt-<arrow> */ /* ESC [ 1 ; 8 x, where x = A/B/C/D: Ctrl-Alt-Shift-<arrow> */ '[','H' |0x80,KEYCODE_HOME , /* xterm */ '[','F' |0x80,KEYCODE_END , /* xterm */ /* [ESC] ESC [ [2] H - [Alt-][Shift-]Home (End similarly?) */ /* '[','Z' |0x80,KEYCODE_SHIFT_TAB, */ '[','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 , /* old xterm, deprecated by ESC O P */ '[','1','2','~'|0x80,KEYCODE_FUN2 , /* old xterm... */ '[','1','3','~'|0x80,KEYCODE_FUN3 , /* old xterm... */ '[','1','4','~'|0x80,KEYCODE_FUN4 , /* old xterm... */ '[','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 , /* '[','1',';','3','A' |0x80,KEYCODE_ALT_UP , - unused */ /* '[','1',';','3','B' |0x80,KEYCODE_ALT_DOWN , - unused */ '[','1',';','3','C' |0x80,KEYCODE_ALT_RIGHT, '[','1',';','3','D' |0x80,KEYCODE_ALT_LEFT , /* '[','3',';','3','~' |0x80,KEYCODE_ALT_DELETE, - unused */ 0 }; 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 || ENABLE_FEATURE_VI_ASK_TERMINAL || ENABLE_FEATURE_LESS_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; }