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1 /* interestingtimes.c - cursor control
2  *
3  * Copyright 2015 Rob Landley <rob@landley.net>
4  */
5 
6 #include "toys.h"
7 
tty_fd(void)8 int tty_fd(void)
9 {
10   int i, j;
11 
12   for (i = 0; i<3; i++) if (isatty(j = (i+1)%3)) return j;
13 
14   return notstdio(open("/dev/tty", O_RDWR));
15 }
16 
17 // Quick and dirty query size of terminal, doesn't do ANSI probe fallback.
18 // set x=80 y=25 before calling to provide defaults. Returns 0 if couldn't
19 // determine size.
20 
terminal_size(unsigned * xx,unsigned * yy)21 int terminal_size(unsigned *xx, unsigned *yy)
22 {
23   struct winsize ws;
24   unsigned i, x = 0, y = 0;
25   char *s;
26 
27   // stdin, stdout, stderr
28   for (i=0; i<3; i++) {
29     memset(&ws, 0, sizeof(ws));
30     if (isatty(i) && !ioctl(i, TIOCGWINSZ, &ws)) {
31       if (ws.ws_col) x = ws.ws_col;
32       if (ws.ws_row) y = ws.ws_row;
33 
34       break;
35     }
36   }
37   s = getenv("COLUMNS");
38   if (s) sscanf(s, "%u", &x);
39   s = getenv("LINES");
40   if (s) sscanf(s, "%u", &y);
41 
42   // Never return 0 for either value, leave it at default instead.
43   if (xx && x) *xx = x;
44   if (yy && y) *yy = y;
45 
46   return x || y;
47 }
48 
49 // Query terminal size, sending ANSI probe if necesary. (Probe queries xterm
50 // size through serial connection, when local TTY doesn't know but remote does.)
51 // Returns 0 if ANSI probe sent, 1 if size determined from tty or environment
52 
terminal_probesize(unsigned * xx,unsigned * yy)53 int terminal_probesize(unsigned *xx, unsigned *yy)
54 {
55   if (terminal_size(xx, yy) && (!xx || *xx) && (!yy || *yy)) return 1;
56 
57   // Send probe: bookmark cursor position, jump to bottom right,
58   // query position, return cursor to bookmarked position.
59   xprintf("\033[s\033[999C\033[999B\033[6n\033[u");
60 
61   return 0;
62 }
63 
xsetspeed(struct termios * tio,int speed)64 void xsetspeed(struct termios *tio, int speed)
65 {
66   int i, speeds[] = {50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
67                     4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800,
68                     500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
69                     2500000, 3000000, 3500000, 4000000};
70 
71   // Find speed in table, adjust to constant
72   for (i = 0; i < ARRAY_LEN(speeds); i++) if (speeds[i] == speed) break;
73   if (i == ARRAY_LEN(speeds)) error_exit("unknown speed: %d", speed);
74   cfsetspeed(tio, i+1+4081*(i>15));
75 }
76 
77 
78 // Reset terminal to known state, saving copy of old state if old != NULL.
set_terminal(int fd,int raw,int speed,struct termios * old)79 int set_terminal(int fd, int raw, int speed, struct termios *old)
80 {
81   struct termios termio;
82   int i = tcgetattr(fd, &termio);
83 
84   // Fetch local copy of old terminfo, and copy struct contents to *old if set
85   if (i) return i;
86   if (old) *old = termio;
87 
88   // the following are the bits set for an xterm. Linux text mode TTYs by
89   // default add two additional bits that only matter for serial processing
90   // (turn serial line break into an interrupt, and XON/XOFF flow control)
91 
92   // Any key unblocks output, swap CR and NL on input
93   termio.c_iflag = IXANY|ICRNL|INLCR;
94   if (toys.which->flags & TOYFLAG_LOCALE) termio.c_iflag |= IUTF8;
95 
96   // Output appends CR to NL, does magic undocumented postprocessing
97   termio.c_oflag = ONLCR|OPOST;
98 
99   // Leave serial port speed alone
100   // termio.c_cflag = C_READ|CS8|EXTB;
101 
102   // Generate signals, input entire line at once, echo output
103   // erase, line kill, escape control characters with ^
104   // erase line char at a time
105   // "extended" behavior: ctrl-V quotes next char, ctrl-R reprints unread chars,
106   // ctrl-W erases word
107   termio.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN;
108 
109   if (raw) cfmakeraw(&termio);
110 
111   if (speed) {
112     int i, speeds[] = {50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
113                     4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800,
114                     500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
115                     2500000, 3000000, 3500000, 4000000};
116 
117     // Find speed in table, adjust to constant
118     for (i = 0; i < ARRAY_LEN(speeds); i++) if (speeds[i] == speed) break;
119     if (i == ARRAY_LEN(speeds)) error_exit("unknown speed: %d", speed);
120     cfsetspeed(&termio, i+1+4081*(i>15));
121   }
122 
123   return tcsetattr(fd, TCSAFLUSH, &termio);
124 }
125 
xset_terminal(int fd,int raw,int speed,struct termios * old)126 void xset_terminal(int fd, int raw, int speed, struct termios *old)
127 {
128   if (-1 != set_terminal(fd, raw, speed, old)) return;
129 
130   sprintf(libbuf, "/proc/self/fd/%d", fd);
131   libbuf[readlink0(libbuf, libbuf, sizeof(libbuf))] = 0;
132   perror_exit("tcsetattr %s", libbuf);
133 }
134 
135 struct scan_key_list {
136   int key;
137   char *seq;
138 } static const scan_key_list[] = {
139   {KEY_UP, "\033[A"}, {KEY_DOWN, "\033[B"},
140   {KEY_RIGHT, "\033[C"}, {KEY_LEFT, "\033[D"},
141 
142   {KEY_UP|KEY_SHIFT, "\033[1;2A"}, {KEY_DOWN|KEY_SHIFT, "\033[1;2B"},
143   {KEY_RIGHT|KEY_SHIFT, "\033[1;2C"}, {KEY_LEFT|KEY_SHIFT, "\033[1;2D"},
144 
145   {KEY_UP|KEY_ALT, "\033[1;3A"}, {KEY_DOWN|KEY_ALT, "\033[1;3B"},
146   {KEY_RIGHT|KEY_ALT, "\033[1;3C"}, {KEY_LEFT|KEY_ALT, "\033[1;3D"},
147 
148   {KEY_UP|KEY_CTRL, "\033[1;5A"}, {KEY_DOWN|KEY_CTRL, "\033[1;5B"},
149   {KEY_RIGHT|KEY_CTRL, "\033[1;5C"}, {KEY_LEFT|KEY_CTRL, "\033[1;5D"},
150 
151   // VT102/VT220 escapes.
152   {KEY_HOME, "\033[1~"},
153   {KEY_INSERT, "\033[2~"},
154   {KEY_DELETE, "\033[3~"},
155   {KEY_END, "\033[4~"},
156   {KEY_PGUP, "\033[5~"},
157   {KEY_PGDN, "\033[6~"},
158   // "Normal" "PC" escapes (xterm).
159   {KEY_HOME, "\033OH"},
160   {KEY_END, "\033OF"},
161   // "Application" "PC" escapes (gnome-terminal).
162   {KEY_HOME, "\033[H"},
163   {KEY_END, "\033[F"},
164 
165   {KEY_FN+1, "\033OP"}, {KEY_FN+2, "\033OQ"}, {KEY_FN+3, "\033OR"},
166   {KEY_FN+4, "\033OS"}, {KEY_FN+5, "\033[15~"}, {KEY_FN+6, "\033[17~"},
167   {KEY_FN+7, "\033[18~"}, {KEY_FN+8, "\033[19~"}, {KEY_FN+9, "\033[20~"},
168 };
169 
170 // Scan stdin for a keypress, parsing known escape sequences, including
171 // responses to screen size queries.
172 // Blocks for timeout_ms milliseconds, 0=return immediately, -1=wait forever.
173 // Returns 0-255=literal, -1=EOF, -2=TIMEOUT, -3=RESIZE, 256+= a KEY_ constant.
174 // Scratch space is necessary because last char of !seq could start new seq.
175 // Zero out first byte of scratch before first call to scan_key.
scan_key_getsize(char * scratch,int timeout_ms,unsigned * xx,unsigned * yy)176 int scan_key_getsize(char *scratch, int timeout_ms, unsigned *xx, unsigned *yy)
177 {
178   struct pollfd pfd;
179   int maybe, i, j;
180   char *test;
181 
182   for (;;) {
183     pfd.fd = 0;
184     pfd.events = POLLIN;
185     pfd.revents = 0;
186 
187     maybe = 0;
188     if (*scratch) {
189       int pos[6];
190       unsigned x, y;
191 
192       // Check for return from terminal size probe
193       memset(pos, 0, 6*sizeof(int));
194       scratch[(1+*scratch)&15] = 0;
195       sscanf(scratch+1, "\033%n[%n%3u%n;%n%3u%nR%n", pos, pos+1, &y,
196              pos+2, pos+3, &x, pos+4, pos+5);
197       if (pos[5]) {
198         // Recognized X/Y position, consume and return
199         *scratch = 0;
200         if (xx) *xx = x;
201         if (yy) *yy = y;
202         return -3;
203       } else for (i=0; i<6; i++) if (pos[i]==*scratch) maybe = 1;
204 
205       // Check sequences
206       for (i = 0; i<ARRAY_LEN(scan_key_list); i++) {
207         test = scan_key_list[i].seq;
208         for (j = 0; j<*scratch; j++) if (scratch[j+1] != test[j]) break;
209         if (j == *scratch) {
210           maybe = 1;
211           if (!test[j]) {
212             // We recognized current sequence: consume and return
213             *scratch = 0;
214             return 256+scan_key_list[i].key;
215           }
216         }
217       }
218 
219       // If current data can't be a known sequence, return next raw char
220       if (!maybe) break;
221     }
222 
223     // Need more data to decide
224 
225     // 30ms is about the gap between characters at 300 baud
226     if (maybe || timeout_ms != -1)
227       if (!xpoll(&pfd, 1, maybe ? 30 : timeout_ms)) break;
228 
229     // Read 1 byte so we don't overshoot sequence match. (We can deviate
230     // and fail to match, but match consumes entire buffer.)
231     if (toys.signal>0 || 1 != read(0, scratch+1+*scratch, 1))
232       return (toys.signal>0) ? -3 : -1;
233     ++*scratch;
234   }
235 
236   // Was not a sequence
237   if (!*scratch) return -2;
238   i = scratch[1];
239   if (--*scratch) memmove(scratch+1, scratch+2, *scratch);
240 
241   return i;
242 }
243 
244 // Wrapper that ignores results from ANSI probe to update screensize.
245 // Otherwise acts like scan_key_getsize().
scan_key(char * scratch,int timeout_ms)246 int scan_key(char *scratch, int timeout_ms)
247 {
248   return scan_key_getsize(scratch, timeout_ms, NULL, NULL);
249 }
250 
tty_esc(char * s)251 void tty_esc(char *s)
252 {
253   printf("\033[%s", s);
254 }
255 
tty_jump(int x,int y)256 void tty_jump(int x, int y)
257 {
258   char s[32];
259 
260   sprintf(s, "%d;%dH", y+1, x+1);
261   tty_esc(s);
262 }
263 
tty_reset(void)264 void tty_reset(void)
265 {
266   set_terminal(0, 0, 0, 0);
267   tty_esc("?25h");
268   tty_esc("0m");
269   tty_jump(0, 999);
270   tty_esc("K");
271   fflush(0);
272 }
273 
274 // If you call set_terminal(), use sigatexit(tty_sigreset);
tty_sigreset(int i)275 void tty_sigreset(int i)
276 {
277   tty_reset();
278   _exit(i ? 128+i : 0);
279 }
280 
start_redraw(unsigned * width,unsigned * height)281 void start_redraw(unsigned *width, unsigned *height)
282 {
283   // If never signaled, do raw mode setup.
284   if (!toys.signal) {
285     *width = 80;
286     *height = 25;
287     set_terminal(0, 1, 0, 0);
288     sigatexit(tty_sigreset);
289     xsignal(SIGWINCH, generic_signal);
290   }
291   if (toys.signal != -1) {
292     toys.signal = -1;
293     terminal_probesize(width, height);
294   }
295   xprintf("\033[H\033[J");
296 }
297