Add support for redirecting or disabling messages from stdout to elsewhere.

The newly introduced procedure wiiuse_set_output can be used to set the FILE*
used for each of the loglevels LOGLEVEL_ERROR, LOGLEVEL_WARNING, LOGLEVEL_INFO,
and LOGLEVEL_DEBUG. Setting the logfile to 0 disables log output for a
loglevel. This adds the macro definition WIIUSE_HAS_OUTPUT_REDIRECTION, so
programs can test for the feature.

The internal log macros in definitions.h all honor this output redirection mechanism.

src/definitions.h

@@ -41,25 +41,34 @@
 
 //#define WITH_WIIUSE_DEBUG
 
+extern FILE* logtarget[];
+
+#define OUTF_ERROR logtarget[0]
+#define OUTF_WARNING logtarget[1]
+#define OUTF_INFO logtarget[2]
+#define OUTF_DEBUG logtarget[3]
+
 /* Error output macros */
-#define WIIUSE_ERROR(fmt, ...)		fprintf(stderr, "[ERROR] " fmt "\n", ##__VA_ARGS__)
+#define WIIUSE_ERROR(fmt, ...)		do { if (OUTF_ERROR) fprintf(OUTF_ERROR, "[ERROR] " fmt "\n", ##__VA_ARGS__); } while(0)
 
 /* Warning output macros */
-#define WIIUSE_WARNING(fmt, ...)	fprintf(stderr, "[WARNING] " fmt "\n",	##__VA_ARGS__)
+#define WIIUSE_WARNING(fmt, ...)	do { if (OUTF_WARNING) fprintf(OUTF_WARNING, "[WARNING] " fmt "\n",	##__VA_ARGS__); } while(0)
 
 /* Information output macros */
-#define WIIUSE_INFO(fmt, ...)		fprintf(stderr, "[INFO] " fmt "\n", ##__VA_ARGS__)
+#define WIIUSE_INFO(fmt, ...)		do { if (OUTF_INFO) fprintf(OUTF_INFO, "[INFO] " fmt "\n", ##__VA_ARGS__); } while(0)
 
 #ifdef WITH_WIIUSE_DEBUG
 	#ifdef WIN32
-		#define WIIUSE_DEBUG(fmt, ...)		do {																				\
+		#define WIIUSE_DEBUG(fmt, ...)		do {																					\
-												char* file = __FILE__;															\
+												if (OUTF_DEBUG) {																	\
-												int i = strlen(file) - 1;														\
+													char* file = __FILE__;															\
-												for (; i && (file[i] != '\\'); --i);											\
+													int i = strlen(file) - 1;														\
-												fprintf(stderr, "[DEBUG] %s:%i: " fmt "\n", file+i+1, __LINE__, ##__VA_ARGS__);	\
+													for (; i && (file[i] != '\\'); --i);											\
+													fprintf(OUTF_DEBUG, "[DEBUG] %s:%i: " fmt "\n", file+i+1, __LINE__, ##__VA_ARGS__);	\
+												}																					\
 											} while (0)
 	#else
-		#define WIIUSE_DEBUG(fmt, ...)	fprintf(stderr, "[DEBUG] " __FILE__ ":%i: " fmt "\n", __LINE__, ##__VA_ARGS__)
+		#define WIIUSE_DEBUG(fmt, ...)	do { if (OUTF_DEBUG) fprintf(OUTF_DEBUG, "[DEBUG] " __FILE__ ":%i: " fmt "\n", __LINE__, ##__VA_ARGS__); } while (0)
 	#endif
 #else
 	#define WIIUSE_DEBUG(fmt, ...)

src/wiiuse.c

@@ -58,6 +58,24 @@ const char* wiiuse_version() {
 	return WIIUSE_VERSION;
 }
 
+/**
+ *	@brief Output FILE stream for each wiiuse_loglevel.
+ */
+FILE* logtarget[4];
+
+/**
+ *	@brief Initialize an array of wiimote structures.
+ *
+ *	@param loglevel The loglevel, for which the output should be set.
+ *
+ *	@param logfile A valid, writeable <code>FILE*</code>, or 0, if output should be disabled.
+ *
+ *  The default <code>FILE*</code> for all loglevels is <code>stderr</code>
+ */
+void wiiuse_set_output(enum wiiuse_loglevel loglevel, FILE *logfile)
+{
+	logtarget[(int)loglevel] = logfile;
+}
 
 /**
  *	@brief Clean up wiimote_t array created by wiiuse_init()
@@ -112,6 +130,11 @@ struct wiimote_t** wiiuse_init(int wiimotes) {
 		g_banner = 1;
 	}
 
+	logtarget[0] = stderr;
+	logtarget[1] = stderr;
+	logtarget[2] = stderr;
+	logtarget[3] = stderr;
+
 	if (!wiimotes)
 		return NULL;
 

src/wiiuse.h

@@ -612,6 +612,16 @@ typedef struct wiimote_t {
 	WCONST byte event_buf[MAX_PAYLOAD];		/**< event buffer							*/
 } wiimote;
 
+/**
+ *	@enum WIIUSE_LOGLEVEL
+ *	@brief Loglevels supported by wiiuse.
+ */
+typedef enum wiiuse_loglevel {
+	LOGLEVEL_ERROR = 0,
+	LOGLEVEL_WARNING = 1,
+	LOGLEVEL_INFO = 2,
+	LOGLEVEL_DEBUG = 3
+} wiiuse_loglevel;
 
 /*****************************************
  *
@@ -639,6 +649,8 @@ extern "C" {
 
 /* wiiuse.c */
 WIIUSE_EXPORT extern const char* wiiuse_version();
+#define WIIUSE_HAS_OUTPUT_REDIRECTION
+WIIUSE_EXPORT extern void wiiuse_set_output(enum wiiuse_loglevel loglevel, FILE *logtarget);
 
 WIIUSE_EXPORT extern struct wiimote_t** wiiuse_init(int wiimotes);
 WIIUSE_EXPORT extern void wiiuse_disconnected(struct wiimote_t* wm);