1 /* tty.c - cursor control
2 *
3 * Copyright 2015 Rob Landley <rob@landley.net>
4 *
5 * Common ANSI (See https://man7.org/linux/man-pages/man4/console_codes.4.html)
6 * \e[#m - color change \e[y;xH - jump to x/y pos (1;1 is top left)
7 * \e[K - delete to EOL \e[25l - disable cursor (h to enable)
8 * \e[1L - Insert 1 (blank) line \e[1M - Delete 1 line (scrolling rest up)
9 * \e[2J - clear screen
10 *
11 * colors: 0=black 1=red 2=green 3=brown 4=blue 5=purple 6=cyan 7=grey
12 * +30 foreground, +40 background.
13 * \e[1m = bright, \e[2m = dark, \e[0m = reset to defaults
14 * \e[1;32;2;42mhello\e[0m - dark green text on light green background
15 */
16
17 #include "toys.h"
18
tty_fd(void)19 int tty_fd(void)
20 {
21 int i, j;
22
23 for (i = 0; i<3; i++) if (isatty(j = (i+1)%3)) return j;
24
25 return xnotstdio(open("/dev/tty", O_RDWR));
26 }
27
28 // Query size of terminal (without ANSI probe fallback).
29 // set x=80 y=25 before calling to provide defaults. Returns 0 if couldn't
30 // determine size.
31
terminal_size(unsigned * xx,unsigned * yy)32 int terminal_size(unsigned *xx, unsigned *yy)
33 {
34 struct winsize ws;
35 unsigned i, x = 0, y = 0;
36 char *s;
37
38 // Check stdin, stdout, stderr
39 for (i = 0; i<3; i++) {
40 memset(&ws, 0, sizeof(ws));
41 if (isatty(i) && !ioctl(i, TIOCGWINSZ, &ws)) {
42 if (ws.ws_col) x = ws.ws_col;
43 if (ws.ws_row) y = ws.ws_row;
44
45 break;
46 }
47 }
48 s = getenv("COLUMNS");
49 if (s) sscanf(s, "%u", &x);
50 s = getenv("LINES");
51 if (s) sscanf(s, "%u", &y);
52
53 // Never return 0 for either value, leave it at default instead.
54 if (xx && x) *xx = x;
55 if (yy && y) *yy = y;
56
57 return x || y;
58 }
59
60 // Query terminal size, sending ANSI probe if necesary. (Probe queries xterm
61 // size through serial connection, when local TTY doesn't know but remote does.)
62 // Returns 0 if ANSI probe sent, 1 if size determined from tty or environment
63
terminal_probesize(unsigned * xx,unsigned * yy)64 int terminal_probesize(unsigned *xx, unsigned *yy)
65 {
66 if (terminal_size(xx, yy) && (!xx || *xx) && (!yy || *yy)) return 1;
67
68 // Send probe: bookmark cursor position, jump to bottom right,
69 // query position, return cursor to bookmarked position.
70 xprintf("\e[s\e[999C\e[999B\e[6n\e[u");
71
72 return 0;
73 }
74
xsetspeed(struct termios * tio,int speed)75 void xsetspeed(struct termios *tio, int speed)
76 {
77 int i, speeds[] = {50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
78 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800,
79 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
80 2500000, 3000000, 3500000, 4000000};
81
82 // Find speed in table, adjust to constant
83 for (i = 0; i < ARRAY_LEN(speeds); i++) if (speeds[i] == speed) break;
84 if (i == ARRAY_LEN(speeds)) error_exit("unknown speed: %d", speed);
85 cfsetspeed(tio, i+1+4081*(i>15));
86 }
87
88
89 // Reset terminal to known state, saving copy of old state if old != NULL.
set_terminal(int fd,int raw,int speed,struct termios * old)90 int set_terminal(int fd, int raw, int speed, struct termios *old)
91 {
92 struct termios termio;
93 int i = tcgetattr(fd, &termio);
94
95 // Fetch local copy of old terminfo, and copy struct contents to *old if set
96 if (i) return i;
97 if (old) *old = termio;
98
99 // the following are the bits set for an xterm. Linux text mode TTYs by
100 // default add two additional bits that only matter for serial processing
101 // (turn serial line break into an interrupt, and XON/XOFF flow control)
102
103 // Any key unblocks output, swap CR and NL on input
104 termio.c_iflag = IXANY|ICRNL|INLCR;
105 if (toys.which->flags & TOYFLAG_LOCALE) termio.c_iflag |= IUTF8;
106
107 // Output appends CR to NL, does magic undocumented postprocessing
108 termio.c_oflag = ONLCR|OPOST;
109
110 // Leave serial port speed alone
111 // termio.c_cflag = C_READ|CS8|EXTB;
112
113 // Generate signals, input entire line at once, echo output
114 // erase, line kill, escape control characters with ^
115 // erase line char at a time
116 // "extended" behavior: ctrl-V quotes next char, ctrl-R reprints unread chars,
117 // ctrl-W erases word
118 termio.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN;
119
120 if (raw) cfmakeraw(&termio);
121
122 if (speed) {
123 int i, speeds[] = {50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
124 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800,
125 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
126 2500000, 3000000, 3500000, 4000000};
127
128 // Find speed in table, adjust to constant
129 for (i = 0; i < ARRAY_LEN(speeds); i++) if (speeds[i] == speed) break;
130 if (i == ARRAY_LEN(speeds)) error_exit("unknown speed: %d", speed);
131 cfsetspeed(&termio, i+1+4081*(i>15));
132 }
133
134 return tcsetattr(fd, TCSAFLUSH, &termio);
135 }
136
xset_terminal(int fd,int raw,int speed,struct termios * old)137 void xset_terminal(int fd, int raw, int speed, struct termios *old)
138 {
139 if (-1 != set_terminal(fd, raw, speed, old)) return;
140
141 sprintf(libbuf, "/proc/self/fd/%d", fd);
142 libbuf[readlink0(libbuf, libbuf, sizeof(libbuf))] = 0;
143 perror_exit("tcsetattr %s", libbuf);
144 }
145
146 struct scan_key_list {
147 int key;
148 char *seq;
149 } static const scan_key_list[] = {
150 {KEY_UP, "\e[A"}, {KEY_DOWN, "\e[B"},
151 {KEY_RIGHT, "\e[C"}, {KEY_LEFT, "\e[D"},
152
153 {KEY_UP|KEY_SHIFT, "\e[1;2A"}, {KEY_DOWN|KEY_SHIFT, "\e[1;2B"},
154 {KEY_RIGHT|KEY_SHIFT, "\e[1;2C"}, {KEY_LEFT|KEY_SHIFT, "\e[1;2D"},
155
156 {KEY_UP|KEY_ALT, "\e[1;3A"}, {KEY_DOWN|KEY_ALT, "\e[1;3B"},
157 {KEY_RIGHT|KEY_ALT, "\e[1;3C"}, {KEY_LEFT|KEY_ALT, "\e[1;3D"},
158
159 {KEY_UP|KEY_CTRL, "\e[1;5A"}, {KEY_DOWN|KEY_CTRL, "\e[1;5B"},
160 {KEY_RIGHT|KEY_CTRL, "\e[1;5C"}, {KEY_LEFT|KEY_CTRL, "\e[1;5D"},
161
162 // VT102/VT220 escapes.
163 {KEY_HOME, "\e[1~"},
164 {KEY_HOME|KEY_CTRL, "\e[1;5~"},
165 {KEY_INSERT, "\e[2~"},
166 {KEY_DELETE, "\e[3~"},
167 {KEY_END, "\e[4~"},
168 {KEY_END|KEY_CTRL, "\e[4;5~"},
169 {KEY_PGUP, "\e[5~"},
170 {KEY_PGDN, "\e[6~"},
171 // "Normal" "PC" escapes (xterm).
172 {KEY_HOME, "\eOH"},
173 {KEY_END, "\eOF"},
174 // "Application" "PC" escapes (gnome-terminal).
175 {KEY_HOME, "\e[H"},
176 {KEY_END, "\e[F"},
177 {KEY_HOME|KEY_CTRL, "\e[1;5H"},
178 {KEY_END|KEY_CTRL, "\e[1;5F"},
179
180 {KEY_FN+1, "\eOP"}, {KEY_FN+2, "\eOQ"}, {KEY_FN+3, "\eOR"},
181 {KEY_FN+4, "\eOS"}, {KEY_FN+5, "\e[15~"}, {KEY_FN+6, "\e[17~"},
182 {KEY_FN+7, "\e[18~"}, {KEY_FN+8, "\e[19~"}, {KEY_FN+9, "\e[20~"},
183 };
184
185 // Scan stdin for a keypress, parsing known escape sequences, including
186 // responses to screen size queries.
187 // Blocks for timeout_ms milliseconds, 0=return immediately, -1=wait forever.
188 // Returns 0-255=literal, -1=EOF, -2=TIMEOUT, -3=RESIZE, 256+= a KEY_ constant.
189 // Scratch space is necessary because last char of !seq could start new seq.
190 // Zero out first byte of scratch before first call to scan_key.
scan_key_getsize(char * scratch,int timeout_ms,unsigned * xx,unsigned * yy)191 int scan_key_getsize(char *scratch, int timeout_ms, unsigned *xx, unsigned *yy)
192 {
193 struct pollfd pfd;
194 int maybe, i, j;
195 char *test;
196
197 for (;;) {
198 pfd.fd = 0;
199 pfd.events = POLLIN;
200 pfd.revents = 0;
201
202 maybe = 0;
203 if (*scratch) {
204 int pos[6];
205 unsigned x, y;
206
207 // Check for return from terminal size probe
208 memset(pos, 0, 6*sizeof(int));
209 scratch[(1+*scratch)&15] = 0;
210 sscanf(scratch+1, "\e%n[%n%3u%n;%n%3u%nR%n", pos, pos+1, &y,
211 pos+2, pos+3, &x, pos+4, pos+5);
212 if (pos[5]) {
213 // Recognized X/Y position, consume and return
214 *scratch = 0;
215 if (xx) *xx = x;
216 if (yy) *yy = y;
217 return -3;
218 } else for (i=0; i<6; i++) if (pos[i]==*scratch) maybe = 1;
219
220 // Check sequences
221 for (i = 0; i<ARRAY_LEN(scan_key_list); i++) {
222 test = scan_key_list[i].seq;
223 for (j = 0; j<*scratch; j++) if (scratch[j+1] != test[j]) break;
224 if (j == *scratch) {
225 maybe = 1;
226 if (!test[j]) {
227 // We recognized current sequence: consume and return
228 *scratch = 0;
229 return 256+scan_key_list[i].key;
230 }
231 }
232 }
233
234 // If current data can't be a known sequence, return next raw char
235 if (!maybe) break;
236 }
237
238 // Need more data to decide
239
240 // 30ms is about the gap between characters at 300 baud
241 if (maybe || timeout_ms != -1)
242 if (!xpoll(&pfd, 1, maybe ? 30 : timeout_ms)) break;
243
244 // Read 1 byte so we don't overshoot sequence match. (We can deviate
245 // and fail to match, but match consumes entire buffer.)
246 if (toys.signal>0 || 1 != read(0, scratch+1+*scratch, 1))
247 return (toys.signal>0) ? -3 : -1;
248 ++*scratch;
249 }
250
251 // Was not a sequence
252 if (!*scratch) return -2;
253 i = scratch[1];
254 if (--*scratch) memmove(scratch+1, scratch+2, *scratch);
255
256 return i;
257 }
258
259 // Wrapper that ignores results from ANSI probe to update screensize.
260 // Otherwise acts like scan_key_getsize().
scan_key(char * scratch,int timeout_ms)261 int scan_key(char *scratch, int timeout_ms)
262 {
263 return scan_key_getsize(scratch, timeout_ms, NULL, NULL);
264 }
265
tty_reset(void)266 void tty_reset(void)
267 {
268 set_terminal(0, 0, 0, 0);
269 xputsn("\e[?25h\e[0m\e[999H\e[K");
270 }
271
272 // If you call set_terminal(), use sigatexit(tty_sigreset);
tty_sigreset(int i)273 void tty_sigreset(int i)
274 {
275 tty_reset();
276 _exit(i ? 128+i : 0);
277 }
278
start_redraw(unsigned * width,unsigned * height)279 void start_redraw(unsigned *width, unsigned *height)
280 {
281 // If never signaled, do raw mode setup.
282 if (!toys.signal) {
283 *width = 80;
284 *height = 25;
285 set_terminal(0, 1, 0, 0);
286 sigatexit(tty_sigreset);
287 xsignal(SIGWINCH, generic_signal);
288 }
289 if (toys.signal != -1) {
290 toys.signal = -1;
291 terminal_probesize(width, height);
292 }
293 xputsn("\e[H\e[J");
294 }
295