aboutsummaryrefslogtreecommitdiff
path: root/lib/interestingtimes.c
blob: a1aa2b67e52962451e0cd6f57a9ec47557fc0346 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
/* interestingtimes.c - cursor control
 *
 * Copyright 2015 Rob Landley <rob@landley.net>
 */

#include "toys.h"

int tty_fd(void)
{
  int i, j;

  for (i = 0; i<3; i++) if (isatty(j = (i+1)%3)) return j;

  return notstdio(open("/dev/tty", O_RDWR));
}

// Quick and dirty query size of terminal, doesn't do ANSI probe fallback.
// set x=80 y=25 before calling to provide defaults. Returns 0 if couldn't
// determine size.

int terminal_size(unsigned *xx, unsigned *yy)
{
  struct winsize ws;
  unsigned i, x = 0, y = 0;
  char *s;

  // stdin, stdout, stderr
  for (i=0; i<3; i++) {
    memset(&ws, 0, sizeof(ws));
    if (isatty(i) && !ioctl(i, TIOCGWINSZ, &ws)) {
      if (ws.ws_col) x = ws.ws_col;
      if (ws.ws_row) y = ws.ws_row;

      break;
    }
  }
  s = getenv("COLUMNS");
  if (s) sscanf(s, "%u", &x);
  s = getenv("LINES");
  if (s) sscanf(s, "%u", &y);

  // Never return 0 for either value, leave it at default instead.
  if (xx && x) *xx = x;
  if (yy && y) *yy = y;

  return x || y;
}

// Query terminal size, sending ANSI probe if necesary. (Probe queries xterm
// size through serial connection, when local TTY doesn't know but remote does.)
// Returns 0 if ANSI probe sent, 1 if size determined from tty or environment

int terminal_probesize(unsigned *xx, unsigned *yy)
{
  if (terminal_size(xx, yy) && (!xx || *xx) && (!yy || *yy)) return 1;

  // Send probe: bookmark cursor position, jump to bottom right,
  // query position, return cursor to bookmarked position.
  xprintf("\033[s\033[999C\033[999B\033[6n\033[u");

  return 0;
}

// Wrapper that parses results from ANSI probe to update screensize.
// Otherwise acts like scan_key()
int scan_key_getsize(char *scratch, int miliwait, unsigned *xx, unsigned *yy)
{
  int key;

  if (512&(key = scan_key(scratch, miliwait))) {
    if (key>0) {
      if (xx) *xx = (key>>10)&1023;
      if (yy) *yy = (key>>20)&1023;

      return -3;
    }
  }

  return key;
}

// Reset terminal to known state, saving copy of old state if old != NULL.
int set_terminal(int fd, int raw, int speed, struct termios *old)
{
  struct termios termio;
  int i = tcgetattr(fd, &termio);

  // Fetch local copy of old terminfo, and copy struct contents to *old if set
  if (i) return i;
  if (old) *old = termio;

  // the following are the bits set for an xterm. Linux text mode TTYs by
  // default add two additional bits that only matter for serial processing
  // (turn serial line break into an interrupt, and XON/XOFF flow control)

  // Any key unblocks output, swap CR and NL on input
  termio.c_iflag = IXANY|ICRNL|INLCR;
  if (toys.which->flags & TOYFLAG_LOCALE) termio.c_iflag |= IUTF8;

  // Output appends CR to NL, does magic undocumented postprocessing
  termio.c_oflag = ONLCR|OPOST;

  // Leave serial port speed alone
  // termio.c_cflag = C_READ|CS8|EXTB;

  // Generate signals, input entire line at once, echo output
  // erase, line kill, escape control characters with ^
  // erase line char at a time
  // "extended" behavior: ctrl-V quotes next char, ctrl-R reprints unread chars,
  // ctrl-W erases word
  termio.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN;

  if (raw) cfmakeraw(&termio);

  if (speed) {
    int i, speeds[] = {50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
                    4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800,
                    500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
                    2500000, 3000000, 3500000, 4000000};

    // Find speed in table, adjust to constant
    for (i = 0; i < ARRAY_LEN(speeds); i++) if (speeds[i] == speed) break;
    if (i == ARRAY_LEN(speeds)) error_exit("unknown speed: %d", speed);
    cfsetspeed(&termio, i+1+4081*(i>15));
  }

  return tcsetattr(fd, TCSAFLUSH, &termio);
}

void xset_terminal(int fd, int raw, int speed, struct termios *old)
{
  if (-1 != set_terminal(fd, raw, speed, old)) return;

  sprintf(libbuf, "/proc/self/fd/%d", fd);
  libbuf[readlink0(libbuf, libbuf, sizeof(libbuf))] = 0;
  perror_exit("tcsetattr %s", libbuf);
}

struct scan_key_list {
  char *name, *seq;
} static const scan_key_list[] = TAGGED_ARRAY(KEY,
  // up down right left pgup pgdn home end ins
  {"UP", "\033[A"}, {"DOWN", "\033[B"}, {"RIGHT", "\033[C"}, {"LEFT", "\033[D"},
  {"PGUP", "\033[5~"}, {"PGDN", "\033[6~"}, {"HOME", "\033OH"},
  {"END", "\033OF"}, {"INSERT", "\033[2~"},

  {"F1", "\033OP"}, {"F2", "\033OQ"}, {"F3", "\033OR"}, {"F4", "\033OS"},
  {"F5", "\033[15~"}, {"F6", "\033[17~"}, {"F7", "\033[18~"},
  {"F8", "\033[19~"}, {"F9", "\033[20~"},

  {"SUP", "\033[1;2A"}, {"AUP", "\033[1;3A"}, {"CUP", "\033[1;5A"},
  {"SDOWN", "\033[1;2B"}, {"ADOWN", "\033[1;3B"}, {"CDOWN", "\033[1;5B"},
  {"SRIGHT", "\033[1;2C"}, {"ARIGHT", "\033[1;3C"}, {"CRIGHT", "\033[1;5C"},
  {"SLEFT", "\033[1;2D"}, {"ALEFT", "\033[1;3D"}, {"CLEFT", "\033[1;5D"},

  {"SF1", "\033O1;2P"}, {"AF1", "\033O1;3P"}, {"CF1", "\033[1;5P"}
);

// Scan stdin for a keypress, parsing known escape sequences
// Blocks for miliwait miliseconds, none 0, forever if -1
// Returns: 0-255=literal, -1=EOF, -2=TIMEOUT, 256-...=index into scan_key_list
// >512 is x<<9+y<<21
// scratch space is necessary because last char of !seq could start new seq
// Zero out first byte of scratch before first call to scan_key
// block=0 allows fetching multiple characters before updating display
int scan_key(char *scratch, int miliwait)
{
  struct pollfd pfd;
  int maybe, i, j;
  char *test;

  for (;;) {
    pfd.fd = 0;
    pfd.events = POLLIN;
    pfd.revents = 0;

    maybe = 0;
    if (*scratch) {
      int pos[6];
      unsigned x, y;

      // Check for return from terminal size probe
      memset(pos, 0, 6*sizeof(int));
      scratch[(1+*scratch)&15] = 0;
      sscanf(scratch+1, "\033%n[%n%3u%n;%n%3u%nR%n", pos, pos+1, &y,
             pos+2, pos+3, &x, pos+4, pos+5);
      if (pos[5]) {
        // Recognized X/Y position, consume and return
        *scratch = 0;
        return 512+(x<<10)+(y<<20);
      } else for (i=0; i<6; i++) if (pos[i]==*scratch) maybe = 1;

      // Check sequences
      for (i = 0; i<ARRAY_LEN(scan_key_list); i++) {
        test = scan_key_list[i].seq;
        for (j = 0; j<*scratch; j++) if (scratch[j+1] != test[j]) break;
        if (j == *scratch) {
          maybe = 1;
          if (!test[j]) {
            // We recognized current sequence: consume and return
            *scratch = 0;
            return 256+i;
          }
        }
      }

      // If current data can't be a known sequence, return next raw char
      if (!maybe) break;
    }

    // Need more data to decide

    // 30 miliseconds is about the gap between characters at 300 baud 
    if (maybe || miliwait != -1)
      if (!xpoll(&pfd, 1, maybe ? 30 : miliwait)) break;

    // Read 1 byte so we don't overshoot sequence match. (We can deviate
    // and fail to match, but match consumes entire buffer.)
    if (toys.signal>0 || 1 != read(0, scratch+1+*scratch, 1))
      return (toys.signal>0) ? -3 : -1;
    ++*scratch;
  }

  // Was not a sequence
  if (!*scratch) return -2;
  i = scratch[1];
  if (--*scratch) memmove(scratch+1, scratch+2, *scratch);

  return i;
}

void tty_esc(char *s)
{
  printf("\033[%s", s);
}

void tty_jump(int x, int y)
{
  char s[32];

  sprintf(s, "%d;%dH", y+1, x+1);
  tty_esc(s);
}

void tty_reset(void)
{
  set_terminal(0, 0, 0, 0);
  tty_esc("?25h");
  tty_esc("0m");
  tty_jump(0, 999);
  tty_esc("K");
  fflush(0);
}

// If you call set_terminal(), use sigatexit(tty_sigreset);
void tty_sigreset(int i)
{
  tty_reset();
  _exit(i ? 128+i : 0);
}

void start_redraw(unsigned *width, unsigned *height)
{
  // If never signaled, do raw mode setup.
  if (!toys.signal) {
    *width = 80;
    *height = 25;
    set_terminal(0, 1, 0, 0);
    sigatexit(tty_sigreset);
    xsignal(SIGWINCH, generic_signal);
  }
  if (toys.signal != -1) {
    toys.signal = -1;
    terminal_probesize(width, height);
  }
  xprintf("\033[H\033[J");
}