[lttng-dev] [PATCH] lttng-tools conf.c and destroy.c

[Thibault, Daniel]

destroy.c :
* Fix usage() output alignment
* Document and enforce return values of cmd_destroy() and destroy_session()
* Output --help to stdout
* Fix destroy_session() so it removes the config when the current session is explicitly specified
conf.c :
* Fix config_destroy() description to match behaviour
------------------------------
>From 41f3600d9f24fb082ab2e60e61f50960f0ef35eb Tue, 31 Jan 2012 10:12:32 -0500
From: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
Date: Tue, 31 Jan 2012 10:12:19 -0500
Subject: [PATCH] lttng-tools conf.c : Fix config_destroy description to match behaviour; destroy.c : Fix usage output alignment, document and enforce return values, output --help to stdout, fix destroy_session so it removes the config when the current session is explicitly specified

Signed-off-by: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>

diff --git a/src/bin/lttng/commands/destroy.c b/src/bin/lttng/commands/destroy.c
index 39b4e9a..441b858 100644
--- a/src/bin/lttng/commands/destroy.c
+++ b/src/bin/lttng/commands/destroy.c
@@ -52,31 +52,43 @@
 	fprintf(ofp, "get it from the configuration directory (.lttng).\n");
 	fprintf(ofp, "\n");
 	fprintf(ofp, "  -h, --help           Show this help\n");
-	fprintf(ofp, "      --list-options       Simple listing of options\n");
+	fprintf(ofp, "      --list-options   Simple listing of options\n");
 	fprintf(ofp, "\n");
 }
 
 /*
- * Destroy a session removing the config directory and unregistering to the
- * session daemon.
+ * Destroys a session, unregistering it from the session daemon.
+ * If the session is unspecified, the current one is destroyed.
+ * If the current session is destroyed, so is its config file.
+ *
+ * Returns one of the CMD_* result values.
  */
 static int destroy_session()
 {
 	int ret;
-	char *session_name, *path;
+	int destroying_current_session;
+	char *session_name, *cur_session_name, *path;
 
-	if (opt_session_name == NULL) {
-		session_name = get_session_name();
-		if (session_name == NULL) {
-			ret = CMD_ERROR;
-			goto error;
-		}
-	} else {
-		session_name = opt_session_name;
+	cur_session_name = get_session_name();
+	if ((cur_session_name == NULL) && (opt_session_name == NULL)) {
+		ret = CMD_ERROR;
+		goto error;
 	}
+	/* At least one of cur_session_name and opt_session_name is not NULL */
+	session_name = (opt_session_name ? opt_session_name : cur_session_name);
+	/*
+	 * We're destroying the current session in two cases:
+	 * If no explicit session was supplied, or
+	 * the explicit session name matches the current session name's (if it exists)
+	 */
+	destroying_current_session =
+			(opt_session_name == NULL) ||
+			(cur_session_name ?
+					(strcmp(cur_session_name, opt_session_name)==0) : 0);
 
 	ret = lttng_destroy_session(session_name);
 	if (ret < 0) {
+		ret = CMD_ERROR;
 		goto free_name;
 	}
 
@@ -86,7 +98,7 @@
 		goto free_name;
 	}
 
-	if (opt_session_name == NULL) {
+	if (destroying_current_session) {
 		config_destroy(path);
 		MSG("Session %s destroyed at %s", session_name, path);
 	} else {
@@ -96,8 +108,8 @@
 	ret = CMD_SUCCESS;
 
 free_name:
-	if (opt_session_name == NULL) {
-		free(session_name);
+	if (cur_session_name != NULL) {
+		free(cur_session_name);
 	}
 error:
 	return ret;
@@ -105,6 +117,8 @@
 
 /*
  * The 'destroy <options>' first level command
+ *
+ * Returns one of the CMD_* result values.
  */
 int cmd_destroy(int argc, const char **argv)
 {
@@ -117,11 +131,10 @@
 	while ((opt = poptGetNextOpt(pc)) != -1) {
 		switch (opt) {
 		case OPT_HELP:
-			usage(stderr);
+			usage(stdout);
 			goto end;
 		case OPT_LIST_OPTIONS:
 			list_cmd_options(stdout, long_options);
-			ret = CMD_SUCCESS;
 			goto end;
 		default:
 			usage(stderr);
diff --git a/src/bin/lttng/conf.c b/src/bin/lttng/conf.c
index 00991b0..0ff5bf1 100644
--- a/src/bin/lttng/conf.c
+++ b/src/bin/lttng/conf.c
@@ -143,7 +143,7 @@
 /*
  *  config_destroy
  *
- *  Destroys directory config and file config.
+ *  Removes the config file from the config directory.
  */
 void config_destroy(char *path)
 {
------------------------------

Daniel U. Thibault
R & D pour la défense Canada - Valcartier (RDDC Valcartier) / Defence R&D Canada - Valcartier (DRDC Valcartier)
Système de systèmes (SdS) / System of Systems (SoS)
Solutions informatiques et expérimentations (SIE) / Computing Solutions and Experimentations (CSE)
2459 Boul. Pie XI Nord
Québec, QC  G3J 1X5
CANADA
Vox : (418) 844-4000 x4245
Fax : (418) 844-4538
NAC: 918V QSDJ
Gouvernement du Canada / Government of Canada
<http://www.valcartier.drdc-rddc.gc.ca/>