#define VERBOSE(format, ...) do { if (verbose) fprintf(stderr, format, ##__VA_ARGS__); } while (0)
bool verbose = false;
+bool exit_on_escape = true;
char template[] = "/var/lock/TMPXXXXXX";
char lockfile[100];
return val;
}
+void exit_on_escapeseq(const char *buf, int len)
+{
+ static const char escseq[] = "\r~.";
+ static const char *state = escseq+1;
+ int i;
+
+ for (i = 0; i < len; i++) {
+ if (buf[i] == *state) {
+ state++;
+ if (*state == 0)
+ exit(0);
+ } else
+ state = escseq;
+ }
+}
+
+void usage(const char* argv0)
+{
+ fprintf(stderr, "Usage: %s [options] <device>\n", argv0);
+ fprintf(stderr, "Options:\n");
+ fprintf(stderr, " -d [+|-] create short positive/negative pulse on DTR\n");
+ fprintf(stderr, " -e ignore '~.' escape sequence\n");
+ fprintf(stderr, " -n do not switch the device to raw mode\n");
+ fprintf(stderr, " -r [+|-] create short positive/negative pulse on RTS\n");
+ fprintf(stderr, " -s <baudrate>\n");
+ fprintf(stderr, " -v verbose\n");
+}
int main(int argc, char *argv[])
{
atexit(restore_stdin_term);
}
- while ((opt = getopt(argc, argv, "nd::r::s:v")) != -1) {
+ while ((opt = getopt(argc, argv, "nd::er::s:v")) != -1) {
switch (opt) {
case 'd': dtr = dtr_rts_arg(opt); break;
+ case 'e': exit_on_escape = false; break;
case 'n': raw = false; break;
case 'r': rts = dtr_rts_arg(opt); break;
case 's': {
verbose = true;
break;
default: /* '?' */
- fprintf(stderr, "Usage: %s [-s baudrate] [-v] <device>\n", argv[0]);
+ usage(argv[0]);
exit(1);
}
}
if (!dev) {
fprintf(stderr, "No device specified\n");
+ usage(argv[0]);
exit(1);
}
CHECK(write(tmp, pid, strlen(pid)));
close(tmp);
snprintf(lockfile, sizeof(lockfile), "/var/lock/LCK..%s", dev + 5);
+ retry:
if (link(template, lockfile) == -1) {
- perror(lockfile);
- exit(1);
+ tmp = CHECK(open(lockfile, O_RDONLY));
+ CHECK(read(tmp, pid, sizeof(pid)));
+ close(tmp);
+ int p = atoi(pid);
+ char proc[50];
+ snprintf(proc, sizeof(proc), "/proc/%d", p);
+ if (access(proc, F_OK) == 0) {
+ fprintf(stderr, "%s is used by PID %d\n", dev, p);
+ exit(1);
+ }
+ fprintf(stderr, "Stale lock file %s (PID %d) - removing it!\n", lockfile, p);
+ CHECK(unlink(lockfile));
+ goto retry;
}
rm_file(0, template);
on_exit(rm_file, lockfile);
VERBOSE("EOF on stdin\n");
break;
}
+ if (exit_on_escape)
+ exit_on_escapeseq(buf, r1);
r2 = CHECK(write(fd, buf, r1));
if (r1 != r2) {
fprintf(stderr, "Not all data written to %s (%d/%d)\n", dev, r1, r2);