tools/libs: stat: Use const whenever we point to literal strings

literal strings are not meant to be modified. So we should use const
char * rather than char * when we want to store a pointer to them.

Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Wei Liu <wl@xen.org>

tools/libs/stat/xenstat_linux.c

@@ -66,7 +66,7 @@ static const char PROCNETDEV_HEADER[] =
 
 /* We need to get the name of the bridge interface for use with bonding interfaces */
 /* Use excludeName parameter to avoid adding bridges we don't care about, eg. virbr0 */
-static void getBridge(char *excludeName, char *result, size_t resultLen)
+static void getBridge(const char *excludeName, char *result, size_t resultLen)
 {
 	struct dirent *de;
 	DIR *d;
@@ -113,7 +113,7 @@ static int parseNetDevLine(char *line, char *iface, unsigned long long *rxBytes,
 	int num = 19;
 
 	/* Regular exception to parse all the information from /proc/net/dev line */
-	char *regex = "([^:]*):([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)"
+	const char *regex = "([^:]*):([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)"
 			"[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*"
 			"([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)[ ]*([^ ]*)";
 

tools/libs/stat/xenstat_qmp.c

@@ -38,7 +38,7 @@
 
 #include <yajl/yajl_tree.h>
 
-static unsigned char *qmp_query(int, char *);
+static unsigned char *qmp_query(int, const char *);
 
 enum query_blockstats {
     QMP_STATS_RETURN  = 0,
@@ -80,7 +80,7 @@ enum query_block {
 static char *qmp_get_block_image(xenstat_node *node, char *qmp_devname, int qfd)
 {
 	char *tmp, *file = NULL;
-	char *query_block_cmd = "{ \"execute\": \"query-block\" }";
+	const char *query_block_cmd = "{ \"execute\": \"query-block\" }";
 	static const char *const qblock[] = {
 		[ QMP_BLOCK_RETURN  ] = "return",
 		[ QMP_BLOCK_DEVICE  ] = "device",
@@ -264,7 +264,7 @@ done:
 }
 
 /* Write a command via the QMP. Returns number of bytes written */
-static size_t qmp_write(int qfd, char *cmd, size_t cmd_len)
+static size_t qmp_write(int qfd, const char *cmd, size_t cmd_len)
 {
 	size_t pos = 0;
 	ssize_t res;
@@ -317,7 +317,7 @@ static int qmp_read(int qfd, unsigned char **qstats)
 }
 
 /* With the given cmd, query QMP for requested data. Returns allocated buffer containing data or NULL */
-static unsigned char *qmp_query(int qfd, char *cmd)
+static unsigned char *qmp_query(int qfd, const char *cmd)
 {
 	unsigned char *qstats = NULL;
 	int n;
@@ -385,8 +385,8 @@ static int qmp_connect(char *path)
 */
 static void read_attributes_qdisk_dom(xenstat_node *node, domid_t domain)
 {
-	char *cmd_mode = "{ \"execute\": \"qmp_capabilities\" }";
-	char *query_blockstats_cmd = "{ \"execute\": \"query-blockstats\" }";
+	const char *cmd_mode = "{ \"execute\": \"qmp_capabilities\" }";
+	const char *query_blockstats_cmd = "{ \"execute\": \"query-blockstats\" }";
 	unsigned char *qmp_stats, *val;
 	char path[80];
 	int qfd;