| /* 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) |
| { |
| struct pollfd pfd; |
| const char *seq; |
| int n; |
| int c; |
| |
| /* 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 */ |
| /* Ctrl- seems to not affect sequences */ |
| '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 , |
| '[','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 , |
| '[','3','~' |0x80,KEYCODE_DELETE , |
| /* [ESC] ESC [ 3 [;2] ~ - [Alt-][Shift-]Delete */ |
| '[','4','~' |0x80,KEYCODE_END , /* vt100? linux vt? or what? */ |
| '[','5','~' |0x80,KEYCODE_PAGEUP , |
| '[','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 , |
| #endif |
| 0 |
| }; |
| |
| errno = 0; |
| n = (unsigned char) *buffer++; |
| if (n == 0) { |
| /* If no data, block waiting for input. |
| * 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; |
| } |
| |
| /* Grab character to return from buffer */ |
| c = (unsigned char)buffer[0]; |
| n--; |
| if (n) |
| memmove(buffer, buffer + 1, n); |
| |
| /* Only ESC starts ESC sequences */ |
| if (c != 27) |
| goto ret; |
| |
| /* Loop through known ESC sequences */ |
| pfd.fd = fd; |
| pfd.events = POLLIN; |
| 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, |
| * break out of both loops. */ |
| goto ret; |
| } |
| 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) |
| c = -1; /* otherwise it's EOF/error */ |
| goto ret; |
| } |
| 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 */ |
| c = (signed char)seq[i+1]; |
| n = 0; |
| /* n -= i; memmove(...); |
| * would be more correct, |
| * but we never read ahead that much, |
| * and n == i here. */ |
| goto ret; |
| } |
| i++; |
| } |
| } |
| /* We did not find matching sequence, it was a bare ESC. |
| * We possibly read and stored more input in buffer[] by now. */ |
| |
| /* Try to decipher "ESC [ NNN ; NNN R" sequence */ |
| if (ENABLE_FEATURE_EDITING_ASK_TERMINAL |
| && n != 0 |
| && buffer[0] == '[' |
| ) { |
| char *end; |
| unsigned long row, col; |
| |
| while (n < KEYCODE_BUFFER_SIZE-1) { /* 1 for cnt */ |
| 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) |
| c = -1; /* otherwise it's EOF/error */ |
| goto ret; |
| } |
| if (buffer[n++] == 'R') |
| goto got_R; |
| } |
| goto ret; |
| got_R: |
| if (!isdigit(buffer[1])) |
| goto ret; |
| row = strtoul(buffer + 1, &end, 10); |
| if (*end != ';' || !isdigit(end[1])) |
| goto ret; |
| col = strtoul(end + 1, &end, 10); |
| if (*end != 'R') |
| goto ret; |
| if (row < 1 || col < 1 || (row | col) > 0x7fff) |
| goto ret; |
| |
| buffer[-1] = 0; |
| |
| /* Pack into "1 <row15bits> <col16bits>" 32-bit sequence */ |
| c = (((-1 << 15) | row) << 16) | col; |
| /* Return it in high-order word */ |
| return ((int64_t) c << 32) | (uint32_t)KEYCODE_CURSOR_POS; |
| } |
| |
| ret: |
| buffer[-1] = n; |
| return c; |
| } |