1 /* interestingtimes.c - cursor control
2  *
3  * Copyright 2015 Rob Landley <rob@landley.net>
4  */
5 
6 #include "toys.h"
7 
xgettty(void)8 int xgettty(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 xopen("/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 (!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("\e[s\e[999C\e[999B\e[6n\e[u");
60 
61   return 0;
62 }
63 
64 // Wrapper that parses results from ANSI probe to update screensize.
65 // Otherwise acts like scan_key()
scan_key_getsize(char * scratch,int miliwait,unsigned * xx,unsigned * yy)66 int scan_key_getsize(char *scratch, int miliwait, unsigned *xx, unsigned *yy)
67 {
68   int key;
69 
70   if (512&(key = scan_key(scratch, miliwait))) {
71     if (key>0) {
72       if (xx) *xx = (key>>10)&1023;
73       if (yy) *yy = (key>>20)&1023;
74       toys.signal = SIGWINCH;
75 
76       return -3;
77     }
78   }
79 
80   return key;
81 }
82 
83 // Reset terminal to known state, saving copy of old state if old != NULL.
set_terminal(int fd,int raw,struct termios * old)84 int set_terminal(int fd, int raw, struct termios *old)
85 {
86   struct termios termio;
87 
88   // Fetch local copy of old terminfo, and copy struct contents to *old if set
89   if (!tcgetattr(fd, &termio) && old) *old = termio;
90 
91   // the following are the bits set for an xterm. Linux text mode TTYs by
92   // default add two additional bits that only matter for serial processing
93   // (turn serial line break into an interrupt, and XON/XOFF flow control)
94 
95   // Any key unblocks output, swap CR and NL on input
96   termio.c_iflag = IXANY|ICRNL|INLCR;
97   if (toys.which->flags & TOYFLAG_LOCALE) termio.c_iflag |= IUTF8;
98 
99   // Output appends CR to NL, does magic undocumented postprocessing
100   termio.c_oflag = ONLCR|OPOST;
101 
102   // Leave serial port speed alone
103   // termio.c_cflag = C_READ|CS8|EXTB;
104 
105   // Generate signals, input entire line at once, echo output
106   // erase, line kill, escape control characters with ^
107   // erase line char at a time
108   // "extended" behavior: ctrl-V quotes next char, ctrl-R reprints unread chars,
109   // ctrl-W erases word
110   termio.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN;
111 
112   if (raw) cfmakeraw(&termio);
113 
114   return tcsetattr(fd, TCSANOW, &termio);
115 }
116 
xset_terminal(int fd,int raw,struct termios * old)117 void xset_terminal(int fd, int raw, struct termios *old)
118 {
119   if (-1 == set_terminal(fd, raw, old)) perror_exit("bad tty fd#%d", fd);
120 }
121 
122 struct scan_key_list {
123   char *name, *seq;
124 } static const scan_key_list[] = TAGGED_ARRAY(KEY,
125   // up down right left pgup pgdn home end ins
126   {"UP", "\033[A"}, {"DOWN", "\033[B"}, {"RIGHT", "\033[C"}, {"LEFT", "\033[D"},
127   {"PGUP", "\033[5~"}, {"PGDN", "\033[6~"}, {"HOME", "\033OH"},
128   {"END", "\033OF"}, {"INSERT", "\033[2~"},
129 
130   {"F1", "\033OP"}, {"F2", "\033OQ"}, {"F3", "\033OR"}, {"F4", "\033OS"},
131   {"F5", "\033[15~"}, {"F6", "\033[17~"}, {"F7", "\033[18~"},
132   {"F8", "\033[19~"}, {"F9", "\033[20~"},
133 
134   {"SUP", "\033[1;2A"}, {"AUP", "\033[1;3A"}, {"CUP", "\033[1;5A"},
135   {"SDOWN", "\033[1;2B"}, {"ADOWN", "\033[1;3B"}, {"CDOWN", "\033[1;5B"},
136   {"SRIGHT", "\033[1;2C"}, {"ARIGHT", "\033[1;3C"}, {"CRIGHT", "\033[1;5C"},
137   {"SLEFT", "\033[1;2D"}, {"ALEFT", "\033[1;3D"}, {"CLEFT", "\033[1;5D"},
138 
139   {"SF1", "\033O1;2P"}, {"AF1", "\033O1;3P"}, {"CF1", "\033[1;5P"}
140 );
141 
142 // Scan stdin for a keypress, parsing known escape sequences
143 // Blocks for miliwait miliseconds, none 0, forever if -1
144 // Returns: 0-255=literal, -1=EOF, -2=NONE, 256-...=index into scan_key_list
145 // >512 is x<<9+y<<21
146 // scratch space is necessary because last char of !seq could start new seq
147 // Zero out first byte of scratch before first call to scan_key
148 // block=0 allows fetching multiple characters before updating display
scan_key(char * scratch,int miliwait)149 int scan_key(char *scratch, int miliwait)
150 {
151   struct pollfd pfd;
152   int maybe, i, j;
153   char *test;
154 
155   for (;;) {
156     pfd.fd = 0;
157     pfd.events = POLLIN;
158     pfd.revents = 0;
159 
160     maybe = 0;
161     if (*scratch) {
162       int pos[6];
163       unsigned x, y;
164 
165       // Check for return from terminal size probe
166       memset(pos, 0, 6*sizeof(int));
167       scratch[(1+*scratch)&15] = 0;
168       sscanf(scratch+1, "\033%n[%n%3u%n;%n%3u%nR%n", pos, pos+1, &y,
169              pos+2, pos+3, &x, pos+4, pos+5);
170       if (pos[5]) {
171         // Recognized X/Y position, consume and return
172         *scratch = 0;
173         return 512+(x<<10)+(y<<20);
174       } else for (i=0; i<6; i++) if (pos[i]==*scratch) maybe = 1;
175 
176       // Check sequences
177       for (i = 0; i<ARRAY_LEN(scan_key_list); i++) {
178         test = scan_key_list[i].seq;
179         for (j = 0; j<*scratch; j++) if (scratch[j+1] != test[j]) break;
180         if (j == *scratch) {
181           maybe = 1;
182           if (!test[j]) {
183             // We recognized current sequence: consume and return
184             *scratch = 0;
185             return 256+i;
186           }
187         }
188       }
189 
190       // If current data can't be a known sequence, return next raw char
191       if (!maybe) break;
192     }
193 
194     // Need more data to decide
195 
196     // 30 miliseconds is about the gap between characters at 300 baud
197     if (maybe || miliwait != -1)
198       if (!xpoll(&pfd, 1, maybe ? 30 : miliwait)) break;
199 
200     // Read 1 byte so we don't overshoot sequence match. (We can deviate
201     // and fail to match, but match consumes entire buffer.)
202     if (toys.signal || 1 != read(0, scratch+1+*scratch, 1))
203       return toys.signal ? -3 : -1;
204     ++*scratch;
205   }
206 
207   // Was not a sequence
208   if (!*scratch) return -2;
209   i = scratch[1];
210   if (--*scratch) memmove(scratch+1, scratch+2, *scratch);
211 
212   return i;
213 }
214 
tty_esc(char * s)215 void tty_esc(char *s)
216 {
217   printf("\033[%s", s);
218 }
219 
tty_jump(int x,int y)220 void tty_jump(int x, int y)
221 {
222   char s[32];
223 
224   sprintf(s, "%d;%dH", y+1, x+1);
225   tty_esc(s);
226 }
227 
tty_reset(void)228 void tty_reset(void)
229 {
230   set_terminal(1, 0, 0);
231   tty_esc("?25h");
232   tty_esc("0m");
233   tty_jump(0, 999);
234   tty_esc("K");
235   fflush(0);
236 }
237 
238 // If you call set_terminal(), use sigatexit(tty_sigreset);
tty_sigreset(int i)239 void tty_sigreset(int i)
240 {
241   tty_reset();
242   _exit(128+i);
243 }
244