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-rw-r--r--lib/interestingtimes.c124
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diff --git a/lib/interestingtimes.c b/lib/interestingtimes.c
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+/* interestingtimes.c - cursor control
+ *
+ * Copyright 2015 Rob Landley <rob@landley.net>
+ */
+
+#include "toys.h"
+
+// Quick and dirty query size of terminal, doesn't do ANSI probe fallback.
+// set x=80 y=25 before calling to provide defaults. Returns 0 if couldn't
+// determine size.
+
+int terminal_size(unsigned *xx, unsigned *yy)
+{
+ struct winsize ws;
+ unsigned i, x = 0, y = 0;
+ char *s;
+
+ // stdin, stdout, stderr
+ for (i=0; i<3; i++) {
+ memset(&ws, 0, sizeof(ws));
+ if (!ioctl(i, TIOCGWINSZ, &ws)) {
+ if (ws.ws_col) x = ws.ws_col;
+ if (ws.ws_row) y = ws.ws_row;
+
+ break;
+ }
+ }
+ s = getenv("COLUMNS");
+ if (s) sscanf(s, "%u", &x);
+ s = getenv("LINES");
+ if (s) sscanf(s, "%u", &y);
+
+ // Never return 0 for either value, leave it at default instead.
+ if (xx && x) *xx = x;
+ if (yy && y) *yy = y;
+
+ return x || y;
+}
+
+// Reset terminal to known state, saving copy of old state if old != NULL.
+int set_terminal(int fd, int raw, struct termios *old)
+{
+ struct termios termio;
+
+ // Fetch local copy of old terminfo, and copy struct contents to *old if set
+ if (!tcgetattr(fd, &termio) && old) *old = termio;
+
+ // the following are the bits set for an xterm. Linux text mode TTYs by
+ // default add two additional bits that only matter for serial processing
+ // (turn serial line break into an interrupt, and XON/XOFF flow control)
+
+ // Any key unblocks output, swap CR and NL on input
+ termio.c_iflag = IXANY|ICRNL|INLCR;
+ if (toys.which->flags & TOYFLAG_LOCALE) termio.c_iflag |= IUTF8;
+
+ // Output appends CR to NL, does magic undocumented postprocessing
+ termio.c_oflag = ONLCR|OPOST;
+
+ // Leave serial port speed alone
+ // termio.c_cflag = C_READ|CS8|EXTB;
+
+ // Generate signals, input entire line at once, echo output
+ // erase, line kill, escape control characters with ^
+ // erase line char at a time
+ // "extended" behavior: ctrl-V quotes next char, ctrl-R reprints unread chars,
+ // ctrl-W erases word
+ termio.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN;
+
+ if (raw) cfmakeraw(&termio);
+
+ return tcsetattr(fd, TCSANOW, &termio);
+}
+
+// Scan stdin for a keypress, parsing known escape sequences
+// seqs is array of char * strings, ends with NULL ptr
+// Returns: 0-255=literal, -1=EOF, -2=NONE, 256-...=index into seq
+// scratch space is necessary because last char of !seq could start new seq
+// Zero out first byte of scratch before first call to scan_key
+// block=0 allows fetching multiple characters before updating display
+int scan_key(char *scratch, char **seqs, int block)
+{
+ struct pollfd pfd;
+ int maybe, i, j;
+ char *test;
+
+ for (;;) {
+ pfd.fd = 0;
+ pfd.events = POLLIN;
+ pfd.revents = 0;
+
+ // check sequences
+ maybe = 0;
+ if (*scratch) {
+ for (i = maybe = 0; (test = seqs[i]); i++) {
+ for (j = 0; j<*scratch; j++) if (scratch[j+1] != test[j]) break;
+ if (j == *scratch) {
+ maybe = 1;
+ if (!test[j]) {
+ // We recognized current sequence: consume and return
+ *scratch = 0;
+ return 256+i;
+ }
+ }
+ }
+ // If current data can't be a known sequence, return next raw char
+ if (!maybe) break;
+ }
+
+ // Need more data to decide
+
+ // 30 miliseconds is about the gap between characters at 300 baud
+ if (maybe || !block) if (!xpoll(&pfd, 1, 30*maybe)) break;
+
+ if (1 != read(0, scratch+1+*scratch, 1)) return -1;
+ ++*scratch;
+ }
+
+ // Was not a sequence
+ if (!*scratch) return -2;
+ i = scratch[1];
+ if (--*scratch) memmove(scratch+1, scratch+2, *scratch);
+
+ return i;
+}