X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fconf.c;h=7d537d1f6d654ab5dce83fa65adf333ed14e4bf4;hp=9d2bfbb665206b7a239ccf3476416793c0840463;hb=18eace3ba4aeaa6b869c8ad9ec1273381b4cbdee;hpb=10a8a2237343699e3923d87e24dbf2d7fe225377

diff --git a/src/bin/lttng/conf.c b/src/bin/lttng/conf.c
index 9d2bfbb66..7d537d1f6 100644
--- a/src/bin/lttng/conf.c
+++ b/src/bin/lttng/conf.c
@@ -2,9 +2,8 @@
  * Copyright (c)  2011 David Goulet <david.goulet@polymtl.ca>
  *
  * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * as published by the Free Software Foundation; only version 2
- * of the License.
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -25,14 +24,13 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include <common/lttngerr.h>
+#include <common/error.h>
 
 #include "conf.h"
 
 /*
- *  config_get_file_path
- *
- *  Return the path with '/CONFIG_FILENAME' added to it.
+ * Returns the path with '/CONFIG_FILENAME' added to it;
+ * path will be NULL if an error occurs.
  */
 char *config_get_file_path(char *path)
 {
@@ -48,9 +46,8 @@ char *config_get_file_path(char *path)
 }
 
 /*
- *  open_config
- *
- *  Return an open FILE pointer to the config file.
+ * Returns an open FILE pointer to the config file;
+ * on error, NULL is returned.
  */
 static FILE *open_config(char *path, const char *mode)
 {
@@ -75,9 +72,9 @@ error:
 }
 
 /*
- *  create_config_file
- *
- *  Create the empty config file a the path.
+ * Creates the empty config file at the path.
+ * On success, returns 0;
+ * on error, returns -1.
  */
 static int create_config_file(char *path)
 {
@@ -98,9 +95,9 @@ error:
 }
 
 /*
- *  write_config
- *
- *  Append data to the config file in file_path
+ * Append data to the config file in file_path
+ * On success, returns 0;
+ * on error, returns -1.
  */
 static int write_config(char *file_path, size_t size, char *data)
 {
@@ -116,7 +113,7 @@ static int write_config(char *file_path, size_t size, char *data)
 
 	/* Write session name into config file */
 	len = fwrite(data, size, 1, fp);
-	if (len < 1) {
+	if (len != 1) {
 		ret = -1;
 	}
 	fclose(fp);
@@ -125,9 +122,7 @@ end:
 }
 
 /*
- *  config_get_default_path
- *
- *  Return the HOME directory path. Caller MUST NOT free(3) the return pointer.
+ * Returns the HOME directory path. Caller MUST NOT free(3) the return pointer.
  */
 char *config_get_default_path(void)
 {
@@ -135,9 +130,7 @@ char *config_get_default_path(void)
 }
 
 /*
- *  config_destroy
- *
- *  Destroy directory config and file config.
+ * Destroys directory config and file config.
  */
 void config_destroy(char *path)
 {
@@ -149,18 +142,50 @@ void config_destroy(char *path)
 		return;
 	}
 
+	if (!config_exists(config_path)) {
+		goto end;
+	}
+
+	DBG("Removing %s\n", config_path);
 	ret = remove(config_path);
 	if (ret < 0) {
 		perror("remove config file");
 	}
-
+end:
 	free(config_path);
 }
 
 /*
- *  config_read_session_name
- *
- *  Return sesson name from the config file.
+ * Destroys the default config
+ */
+void config_destroy_default(void)
+{
+	char *path = config_get_default_path();
+	if (path == NULL) {
+		return;
+	}
+	config_destroy(path);
+}
+
+/*
+ * Returns 1 if config exists, 0 otherwise
+ */
+int config_exists(const char *path)
+{
+	int ret;
+	struct stat info;
+
+	ret = stat(path, &info);
+	if (ret < 0) {
+		return 0;
+	}
+	return S_ISREG(info.st_mode) || S_ISDIR(info.st_mode);
+}
+
+/*
+ * Returns the session name from the config file.
+ * The caller is responsible for freeing the returned string.
+ * On error, NULL is returned.
  */
 char *config_read_session_name(char *path)
 {
@@ -168,19 +193,24 @@ char *config_read_session_name(char *path)
 	FILE *fp;
 	char var[NAME_MAX], *session_name;
 
+	session_name = malloc(NAME_MAX);
+	if (session_name == NULL) {
+		ERR("Out of memory");
+		goto error;
+	}
+
 	fp = open_config(path, "r");
 	if (fp == NULL) {
 		ERR("Can't find valid lttng config %s/.lttngrc", path);
-		MSG("Did you create a session? (lttng create <my_sesion>)");
+		MSG("Did you create a session? (lttng create <my_session>)");
 		goto error;
 	}
 
-	session_name = malloc(NAME_MAX);
 	while (!feof(fp)) {
 		if ((ret = fscanf(fp, "%[^'=']=%s\n", var, session_name)) != 2) {
 			if (ret == -1) {
 				ERR("Missing session=NAME in config file.");
-				goto error;
+				goto error_close;
 			}
 			continue;
 		}
@@ -190,6 +220,7 @@ char *config_read_session_name(char *path)
 		}
 	}
 
+error_close:
 	fclose(fp);
 
 error:
@@ -202,17 +233,22 @@ found:
 }
 
 /*
- *  config_add_session_name
- *
- *  Write session name option to the config file.
+ * Write session name option to the config file.
+ * On success, returns 0;
+ * on error, returns -1.
  */
 int config_add_session_name(char *path, char *name)
 {
 	int ret;
 	char session_name[NAME_MAX];
 
+	/*
+	 * With GNU C <  2.1, snprintf returns -1 if the target buffer is too small;
+	 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
+	 */
 	ret = snprintf(session_name, NAME_MAX, "session=%s\n", name);
-	if (ret < 0) {
+	if ((ret < 0) || (ret >= NAME_MAX)) {
+		ret = -1;
 		goto error;
 	}
 	ret = write_config(path, ret, session_name);
@@ -221,9 +257,9 @@ error:
 }
 
 /*
- *  config_init
- *
- *  Init configuration directory and file.
+ * Init configuration directory and file.
+ * On success, returns 0;
+ * on error, returns -1.
  */
 int config_init(char *session_name)
 {