X-Git-Url: http://rtime.felk.cvut.cz/gitweb/can-benchmark.git/blobdiff_plain/b2d4cdf3a69ade2a5455fae03a0a99a1f9d631ce..951125868861afc8138dd68896a1bb190931ba3e:/utils/sterm.c

diff --git a/utils/sterm.c b/utils/sterm.c
index a3e9786..0e124e5 100644
--- a/utils/sterm.c
+++ b/utils/sterm.c
@@ -47,9 +47,10 @@
 #define CHECK(cmd) ({ int ret = (cmd); if (ret == -1) { perror(#cmd " line " TOSTRING(__LINE__)); exit(1); }; ret; })
 #define CHECKPTR(cmd) ({ void *ptr = (cmd); if (ptr == (void*)-1) { perror(#cmd " line " TOSTRING(__LINE__)); exit(1); }; ptr; })
 
-#define VERBOSE(format, ...) do { if (verbose) fprintf(stderr, format, ##__VA_ARGS__); } while (0)
+#define VERBOSE(format, ...) do { if (verbose) fprintf(stderr, "sterm: " format, ##__VA_ARGS__); } while (0)
 
 bool verbose = false;
+bool exit_on_escape = true;
 
 char template[] = "/var/lock/TMPXXXXXX";
 char lockfile[100];
@@ -89,6 +90,33 @@ int dtr_rts_arg(const char option)
 	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[])
 {
@@ -106,9 +134,10 @@ 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': {
@@ -145,7 +174,7 @@ int main(int argc, char *argv[])
 			verbose = true;
 			break;
 		default: /* '?' */
-			fprintf(stderr, "Usage: %s [-s baudrate] [-v] <device>\n", argv[0]);
+			usage(argv[0]);
 			exit(1);
 		}
 	}
@@ -155,6 +184,7 @@ int main(int argc, char *argv[])
 
 	if (!dev) {
 		fprintf(stderr, "No device specified\n");
+		usage(argv[0]);
 		exit(1);
 	}
 
@@ -174,9 +204,21 @@ int main(int argc, char *argv[])
 		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);
@@ -230,16 +272,21 @@ int main(int argc, char *argv[])
 		CHECK(tcsetattr(0, TCSANOW, &tio));
 	}
 
-	VERBOSE("Connected.\n");
+	VERBOSE("Connected.\r\n");
+	if (exit_on_escape)
+		VERBOSE("Use '<Enter>~.' sequence to exit.\r\n");
+
 	while (1) {
 		int r1, r2;
 		CHECK(poll(fds, 2, -1));
 		if (fds[0].revents & POLLIN) {
 			r1 = CHECK(read(0, buf, sizeof(buf)));
 			if (r1 == 0) {
-				VERBOSE("EOF on stdin\n");
+				VERBOSE("EOF on stdin\r\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);
@@ -249,7 +296,7 @@ int main(int argc, char *argv[])
 		if (fds[1].revents & POLLIN) {
 			r1 = CHECK(read(fd, buf, sizeof(buf)));
 			if (r1 == 0) {
-				VERBOSE("EOF on %s\n", dev);
+				VERBOSE("EOF on %s\r\n", dev);
 				break;
 			}
 			r2 = CHECK(write(1, buf, r1));