X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fcommands%2Fsnapshot.c;h=298bc6ef36cee6a1bac7cb362464c0dd22f9915c;hb=dad01b0a32248a3accec24e763b354610321d228;hp=ebe1d14aa2e384d04a91bf1cd218c3055e14f043;hpb=50534d6fb4b1f0557b45919c8efad209f68b5e26;p=lttng-tools.git

diff --git a/src/bin/lttng/commands/snapshot.c b/src/bin/lttng/commands/snapshot.c
index ebe1d14aa..298bc6ef3 100644
--- a/src/bin/lttng/commands/snapshot.c
+++ b/src/bin/lttng/commands/snapshot.c
@@ -15,7 +15,7 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 #include <inttypes.h>
 #include <popt.h>
@@ -78,41 +78,6 @@ static struct cmd_struct actions[] = {
 	{ NULL, NULL }	/* Array closure */
 };
 
-/*
- * usage
- */
-static void usage(FILE *ofp)
-{
-	fprintf(ofp, "usage: lttng snapshot [OPTION] ACTION\n");
-	fprintf(ofp, "\n");
-	fprintf(ofp, "Actions:\n");
-	fprintf(ofp, "   add-output [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL>\n");
-	fprintf(ofp, "      Setup and add an snapshot output for a session.\n");
-	fprintf(ofp, "\n");
-	fprintf(ofp, "   del-output ID | NAME [-s <NAME>]\n");
-	fprintf(ofp, "      Delete an output for a session using the ID.\n");
-	fprintf(ofp, "\n");
-	fprintf(ofp, "   list-output [-s <NAME>]\n");
-	fprintf(ofp, "      List the output of a session.\n");
-	fprintf(ofp, "\n");
-	fprintf(ofp, "   record [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>]\n");
-	fprintf(ofp, "      Snapshot a session's buffer(s) for all domains. If an URL is\n");
-	fprintf(ofp, "      specified, it is used instead of a previously added output.\n");
-	fprintf(ofp, "      Specifying only a name or/a size will override the current output value.\n");
-	fprintf(ofp, "      For instance, you can record a snapshot with a custom maximum size\n");
-	fprintf(ofp, "      or with a different name.\n");
-	fprintf(ofp, "\n");
-	fprintf(ofp, "Options:\n");
-	fprintf(ofp, "  -h, --help           Show this help\n");
-	fprintf(ofp, "      --list-options   Simple listing of options\n");
-	fprintf(ofp, "  -s, --session NAME   Apply to session name\n");
-	fprintf(ofp, "  -n, --name NAME      Name of the output or snapshot\n");
-	fprintf(ofp, "  -m, --max-size SIZE  Maximum bytes size of the snapshot {+k,+M,+G}\n");
-	fprintf(ofp, "  -C, --ctrl-url URL   Set control path URL. (Must use -D also)\n");
-	fprintf(ofp, "  -D, --data-url URL   Set data path URL. (Must use -C also)\n");
-	fprintf(ofp, "\n");
-}
-
 /*
  * Count and return the number of arguments in argv.
  */
@@ -294,7 +259,6 @@ static int mi_del_output(uint32_t id, const char *name)
 
 	ret = lttng_snapshot_del_output(current_session_name, output);
 	if (ret < 0) {
-		ret = CMD_FATAL;
 		goto error;
 	}
 
@@ -377,7 +341,6 @@ static int mi_add_output(const char *url)
 	/* This call, if successful, populates the id of the output object. */
 	ret = lttng_snapshot_add_output(current_session_name, output);
 	if (ret < 0) {
-		ret = CMD_ERROR;
 		goto error;
 	}
 
@@ -457,7 +420,6 @@ static int cmd_add_output(int argc, const char **argv)
 	int ret;
 
 	if (argc < 2 && (!opt_data_url || !opt_ctrl_url)) {
-		usage(stderr);
 		ret = CMD_ERROR;
 		goto end;
 	}
@@ -479,7 +441,6 @@ static int cmd_del_output(int argc, const char **argv)
 	long id;
 
 	if (argc < 2) {
-		usage(stderr);
 		ret = CMD_ERROR;
 		goto end;
 	}
@@ -569,9 +530,7 @@ static int record(const char *url)
 	ret = lttng_snapshot_record(current_session_name, output, 0);
 	if (ret < 0) {
 		if (ret == -LTTNG_ERR_MAX_SIZE_INVALID) {
-			ERR("The minimum size of a snapshot is computed by multiplying "
-					"the total amount of streams with the largest subbuffer "
-					"in the session.");
+			ERR("Invalid snapshot size. Cannot fit at least one packet per stream.");
 		}
 		goto error;
 	}
@@ -619,7 +578,6 @@ static int handle_command(const char **argv)
 
 	if (argv == NULL || (!opt_ctrl_url && opt_data_url) ||
 			(opt_ctrl_url && !opt_data_url)) {
-		usage(stderr);
 		command_ret = CMD_ERROR;
 		goto end;
 	}
@@ -672,10 +630,10 @@ static int handle_command(const char **argv)
 		cmd = &actions[i];
 	}
 
-	ret = -CMD_UNDEFINED;
+	ret = CMD_UNDEFINED;
 
 end:
-	/* Overwrite ret if an error occured in cmd->func() */
+	/* Overwrite ret if an error occurred in cmd->func() */
 	ret = command_ret ? command_ret : ret;
 	return ret;
 }
@@ -719,7 +677,7 @@ int cmd_snapshot(int argc, const char **argv)
 	while ((opt = poptGetNextOpt(pc)) != -1) {
 		switch (opt) {
 		case OPT_HELP:
-			usage(stdout);
+			SHOW_HELP();
 			goto end;
 		case OPT_LIST_OPTIONS:
 			list_cmd_options(stdout, snapshot_opts);
@@ -743,7 +701,6 @@ int cmd_snapshot(int argc, const char **argv)
 			break;
 		}
 		default:
-			usage(stderr);
 			ret = CMD_UNDEFINED;
 			goto end;
 		}
@@ -761,13 +718,22 @@ int cmd_snapshot(int argc, const char **argv)
 	}
 
 	command_ret = handle_command(poptGetArgs(pc));
-	if (command_ret < 0) {
+	if (command_ret) {
 		switch (-command_ret) {
 		case LTTNG_ERR_EPERM:
 			ERR("The session needs to be set in no output mode (--no-output)");
 			break;
 		case LTTNG_ERR_SNAPSHOT_NODATA:
 			WARN("%s", lttng_strerror(command_ret));
+
+			/*  A warning is fine since the user has no control on
+			 *  whether or not applications (or the kernel) have
+			 *  produced any event between the start of the tracing
+			 *  session and the recording of the snapshot. MI wise
+			 *  the command is not a success since nothing was
+			 *  recorded.
+			 */
+			command_ret = 0;
 			break;
 		default:
 			ERR("%s", lttng_strerror(command_ret));