Rob Landley | 72cd2e0 | 2015-05-08 20:20:29 -0500 | [diff] [blame] | 1 | /* interestingtimes.c - cursor control |
| 2 | * |
| 3 | * Copyright 2015 Rob Landley <rob@landley.net> |
| 4 | */ |
| 5 | |
| 6 | #include "toys.h" |
| 7 | |
Rob Landley | 5b2644c | 2015-05-14 13:43:01 -0500 | [diff] [blame^] | 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 | |
Rob Landley | 72cd2e0 | 2015-05-08 20:20:29 -0500 | [diff] [blame] | 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 | } |