X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Flttng.c;h=31b4714db11ae59f4a8ad0d104bbebecb58d0bba;hp=aeaad1469725db898871c6a644f1b2a00119d8a7;hb=d16c1a4ce20ed71733c02353383f1a3058fe9ed2;hpb=5a532b6873b6d619381c0188b91e48106e639808

diff --git a/src/bin/lttng/lttng.c b/src/bin/lttng/lttng.c
index aeaad1469..31b4714db 100644
--- a/src/bin/lttng/lttng.c
+++ b/src/bin/lttng/lttng.c
@@ -82,23 +82,23 @@ static struct cmd_struct commands[] =  {
 static void usage(FILE *ofp)
 {
 	fprintf(ofp, "LTTng Trace Control " VERSION"\n\n");
-	fprintf(ofp, "usage: lttng [options] <command>\n");
+	fprintf(ofp, "usage: lttng [OPTIONS] <COMMAND>\n");
 	fprintf(ofp, "\n");
 	fprintf(ofp, "Options:\n");
 	fprintf(ofp, "  -h, --help             Show this help\n");
-	fprintf(ofp, "  -g, --group NAME       Unix tracing group name. (default: tracing)\n");
-	fprintf(ofp, "  -v, --verbose          Verbose mode\n");
+	fprintf(ofp, "      --list-options     Simple listing of lttng options\n");
+	fprintf(ofp, "      --list-commands    Simple listing of lttng commands\n");
+	fprintf(ofp, "  -v, --verbose          Increase verbosity\n");
 	fprintf(ofp, "  -q, --quiet            Quiet mode\n");
+	fprintf(ofp, "  -g, --group NAME       Unix tracing group name. (default: tracing)\n");
 	fprintf(ofp, "  -n, --no-sessiond      Don't spawn a session daemon\n");
 	fprintf(ofp, "      --sessiond-path    Session daemon full path\n");
-	fprintf(ofp, "      --list-options     Simple listing of lttng options\n");
-	fprintf(ofp, "      --list-commands    Simple listing of lttng commands\n");
 	fprintf(ofp, "\n");
 	fprintf(ofp, "Commands:\n");
-	fprintf(ofp, "    add-context     Add context to event or/and channel\n");
+	fprintf(ofp, "    add-context     Add context to event and/or channel\n");
 	fprintf(ofp, "    calibrate       Quantify LTTng overhead\n");
 	fprintf(ofp, "    create          Create tracing session\n");
-	fprintf(ofp, "    destroy         Teardown tracing session\n");
+	fprintf(ofp, "    destroy         Tear down tracing session\n");
 	fprintf(ofp, "    enable-channel  Enable tracing channel\n");
 	fprintf(ofp, "    enable-event    Enable tracing event\n");
 	fprintf(ofp, "    disable-channel Disable tracing channel\n");
@@ -263,6 +263,9 @@ static int handle_command(int argc, char **argv)
 		if (strcmp(argv[0], cmd->name) == 0) {
 			ret = cmd->func(argc, (const char**) argv);
 			switch (ret) {
+			case CMD_WARNING:
+				WARN("Some command(s) went wrong");
+				break;
 			case CMD_ERROR:
 				ERR("Command error");
 				break;
@@ -316,19 +319,20 @@ static int spawn_sessiond(char *pathname)
 	} else if (pid > 0) {
 		sessiond_pid = pid;
 		/*
-		 * Wait for lttng-sessiond to start. We need to use a
-		 * flag to check if the signal has been sent to us,
-		 * because the child can be scheduled before the parent,
-		 * and thus send the signal before this check. In the
-		 * signal handler, we set the recv_child_signal flag, so
-		 * anytime we check it after the fork is fine. Note that
-		 * sleep() is interrupted before the 1 second delay as
-		 * soon as the signal is received, so it will not cause
-		 * visible delay for the user.
+		 * Wait for lttng-sessiond to start. We need to use a flag to check if
+		 * the signal has been sent to us, because the child can be scheduled
+		 * before the parent, and thus send the signal before this check. In
+		 * the signal handler, we set the recv_child_signal flag, so anytime we
+		 * check it after the fork is fine. Note that sleep() is interrupted
+		 * before the 1 second delay as soon as the signal is received, so it
+		 * will not cause visible delay for the user.
 		 */
 		while (!recv_child_signal) {
 			sleep(1);
 		}
+		/*
+		 * The signal handler will nullify sessiond_pid on SIGCHLD
+		 */
 		if (!sessiond_pid) {
 			exit(EXIT_FAILURE);
 		}
@@ -361,7 +365,7 @@ static int check_sessiond(void)
 		if (opt_sessiond_path != NULL) {
 			ret = access(opt_sessiond_path, F_OK | X_OK);
 			if (ret < 0) {
-				ERR("No such file: %s", opt_sessiond_path);
+				ERR("No such file or access denied: %s", opt_sessiond_path);
 				goto end;
 			}
 			pathname = opt_sessiond_path;
@@ -383,7 +387,7 @@ static int check_sessiond(void)
 		ret = spawn_sessiond(pathname);
 		free(alloc_pathname);
 		if (ret < 0) {
-			ERR("Problem occurs when starting %s", pathname);
+			ERR("Problem occurred when starting %s", pathname);
 			goto end;
 		}
 	}
@@ -405,7 +409,8 @@ static int check_args_no_sessiond(int argc, char **argv)
 	for (i = 0; i < argc; i++) {
 		if ((strncmp(argv[i], "-h", sizeof("-h")) == 0) ||
 				strncmp(argv[i], "--h", sizeof("--h")) == 0 ||
-				strncmp(argv[i], "--list-options", sizeof("--list-options")) == 0) {
+				strncmp(argv[i], "--list-options", sizeof("--list-options")) == 0 ||
+				strncmp(argv[i], "--list-commands", sizeof("--list-commands")) == 0) {
 			return 1;
 		}
 	}
@@ -414,10 +419,9 @@ static int check_args_no_sessiond(int argc, char **argv)
 }
 
 /*
- *  parse_args
+ * Parse command line arguments.
  *
- *  Parse command line arguments.
- *  Return 0 if OK, else -1
+ * Return 0 if OK, else -1
  */
 static int parse_args(int argc, char **argv)
 {
@@ -431,8 +435,8 @@ static int parse_args(int argc, char **argv)
 	while ((opt = getopt_long(argc, argv, "+hnvqg:", long_options, NULL)) != -1) {
 		switch (opt) {
 		case 'h':
-			usage(stderr);
-			goto error;
+			usage(stdout);
+			goto end;
 		case 'v':
 			opt_verbose += 1;
 			break;
@@ -451,11 +455,11 @@ static int parse_args(int argc, char **argv)
 		case OPT_DUMP_OPTIONS:
 			list_options(stdout);
 			ret = 0;
-			goto error;
+			goto end;
 		case OPT_DUMP_COMMANDS:
 			list_commands(stdout);
 			ret = 0;
-			goto error;
+			goto end;
 		default:
 			usage(stderr);
 			goto error;
@@ -493,6 +497,7 @@ static int parse_args(int argc, char **argv)
 		goto error;
 	}
 
+end:
 	return 0;
 
 error: