1 /* interestingtimes.c - cursor control 2 * 3 * Copyright 2015 Rob Landley <rob (at) landley.net> 4 */ 5 6 #include "toys.h" 7 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 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 // Reset terminal to known state, saving copy of old state if old != NULL. 50 int set_terminal(int fd, int raw, struct termios *old) 51 { 52 struct termios termio; 53 54 // Fetch local copy of old terminfo, and copy struct contents to *old if set 55 if (!tcgetattr(fd, &termio) && old) *old = termio; 56 57 // the following are the bits set for an xterm. Linux text mode TTYs by 58 // default add two additional bits that only matter for serial processing 59 // (turn serial line break into an interrupt, and XON/XOFF flow control) 60 61 // Any key unblocks output, swap CR and NL on input 62 termio.c_iflag = IXANY|ICRNL|INLCR; 63 if (toys.which->flags & TOYFLAG_LOCALE) termio.c_iflag |= IUTF8; 64 65 // Output appends CR to NL, does magic undocumented postprocessing 66 termio.c_oflag = ONLCR|OPOST; 67 68 // Leave serial port speed alone 69 // termio.c_cflag = C_READ|CS8|EXTB; 70 71 // Generate signals, input entire line at once, echo output 72 // erase, line kill, escape control characters with ^ 73 // erase line char at a time 74 // "extended" behavior: ctrl-V quotes next char, ctrl-R reprints unread chars, 75 // ctrl-W erases word 76 termio.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN; 77 78 if (raw) cfmakeraw(&termio); 79 80 return tcsetattr(fd, TCSANOW, &termio); 81 } 82 83 // Scan stdin for a keypress, parsing known escape sequences 84 // seqs is array of char * strings, ends with NULL ptr 85 // Returns: 0-255=literal, -1=EOF, -2=NONE, 256-...=index into seq 86 // scratch space is necessary because last char of !seq could start new seq 87 // Zero out first byte of scratch before first call to scan_key 88 // block=0 allows fetching multiple characters before updating display 89 int scan_key(char *scratch, char **seqs, int block) 90 { 91 struct pollfd pfd; 92 int maybe, i, j; 93 char *test; 94 95 for (;;) { 96 pfd.fd = 0; 97 pfd.events = POLLIN; 98 pfd.revents = 0; 99 100 // check sequences 101 maybe = 0; 102 if (*scratch) { 103 for (i = maybe = 0; (test = seqs[i]); i++) { 104 for (j = 0; j<*scratch; j++) if (scratch[j+1] != test[j]) break; 105 if (j == *scratch) { 106 maybe = 1; 107 if (!test[j]) { 108 // We recognized current sequence: consume and return 109 *scratch = 0; 110 return 256+i; 111 } 112 } 113 } 114 // If current data can't be a known sequence, return next raw char 115 if (!maybe) break; 116 } 117 118 // Need more data to decide 119 120 // 30 miliseconds is about the gap between characters at 300 baud 121 if (maybe || !block) if (!xpoll(&pfd, 1, 30*maybe)) break; 122 123 if (1 != read(0, scratch+1+*scratch, 1)) return -1; 124 ++*scratch; 125 } 126 127 // Was not a sequence 128 if (!*scratch) return -2; 129 i = scratch[1]; 130 if (--*scratch) memmove(scratch+1, scratch+2, *scratch); 131 132 return i; 133 } 134
