Add a dedicated logging facility (keyd_log)

- Add support for NO_COLOR (#346)
 - Automatically disable colorized output when stdout is not a terminal.

src/config.c

@@ -20,7 +20,7 @@
 #include "keyd.h"
 #include "ini.h"
 #include "keys.h"
-#include "error.h"
+#include "log.h"
 #include "string.h"
 #include "unicode.h"
 
@@ -28,7 +28,7 @@
 #define MAX_LINE_LEN 256
 
 #undef warn
-#define warn(fmt, ...) fprintf(stderr, "\t\033[31;1mERROR:\033[0m "fmt"\n", ##__VA_ARGS__)
+#define warn(fmt, ...) keyd_log("\tr{ERROR:} "fmt"\n", ##__VA_ARGS__)
 
 static struct {
 	const char *name;

src/error.c

@@ -1,9 +0,0 @@
-/*
- * keyd - A key remapping daemon.
- *
- * © 2019 Raheman Vaiya (see also: LICENSE).
- */
-#include "error.h"
-
-char errstr[2048];
-int debug_level;

src/error.h

@@ -1,26 +0,0 @@
-/*
- * keyd - A key remapping daemon.
- *
- * © 2019 Raheman Vaiya (see also: LICENSE).
- */
-#ifndef ERROR_H
-#define ERROR_H
-
-#include <stdio.h>
-
-#define dbg(fmt, ...) { \
-	if (debug_level >= 1) \
-		fprintf(stderr, "DEBUG: %s:%d: "fmt"\n", __FILE__, __LINE__, ##__VA_ARGS__); \
-}
-
-#define dbg2(fmt, ...) { \
-	if (debug_level >= 2) \
-		fprintf(stderr, "DEBUG: %s:%d: "fmt"\n", __FILE__, __LINE__, ##__VA_ARGS__); \
-}
-
-#define err(fmt, ...) snprintf(errstr, sizeof(errstr), fmt, ##__VA_ARGS__);
-
-extern int debug_level;
-extern char errstr[2048];
-
-#endif

src/keyd.c

@@ -219,9 +219,14 @@ int main(int argc, char *argv[])
 {
 	size_t i;
 
-	debug_level =
+	log_level =
 	    atoi(getenv("KEYD_DEBUG") ? getenv("KEYD_DEBUG") : "");
 
+	if (isatty(1))
+		suppress_colours = getenv("NO_COLOR") ? 1 : 0;
+	else
+		suppress_colours = 1;
+
 	dbg("Debug mode activated");
 
 	signal(SIGTERM, exit);

src/log.c

@@ -0,0 +1,80 @@
+/*
+ * keyd - A key remapping daemon.
+ *
+ * © 2019 Raheman Vaiya (see also: LICENSE).
+ */
+#include "log.h"
+#include <time.h>
+
+char errstr[2048];
+
+int log_level = 0;
+int suppress_colours = 0;
+
+static const char *colorize(const char *s)
+{
+	int i;
+
+	static char buf[1024];
+	size_t n  = 0;
+	int inside_escape = 0;
+
+	for (i = 0; s[i] != 0 && n < sizeof(buf); i++) {
+		if (s[i+1] == '{') {
+			int escape_num = 0;
+
+			switch (s[i]) {
+				case 'r': escape_num = 1; break;
+				case 'g': escape_num = 2; break;
+				case 'y': escape_num = 3; break;
+				case 'b': escape_num = 4; break;
+				case 'm': escape_num = 5; break;
+				case 'c': escape_num = 6; break;
+				case 'w': escape_num = 7; break;
+				default: break;
+			}
+
+			if (escape_num) {
+				if (!suppress_colours && (sizeof(buf)-n > 5)) {
+					buf[n++] = '\033';
+					buf[n++] = '[';
+					buf[n++] = '3';
+					buf[n++] = '0' + escape_num;
+					buf[n++] = 'm';
+				}
+
+				inside_escape = 1;
+
+				i++;
+				continue;
+			}
+		}
+
+		if (s[i] == '}' && inside_escape) {
+			if (!suppress_colours && (sizeof(buf)-n > 4)) {
+				memcpy(buf+n, "\033[0m", 4);
+				n += 4;
+			}
+
+			inside_escape = 0;
+			continue;
+		}
+
+		buf[n++] = s[i];
+	}
+
+	buf[n] = 0;
+
+	return buf;
+}
+
+void _keyd_log(int level, const char *fmt, ...)
+{
+	if (level > log_level)
+		return;
+
+	va_list ap;
+	va_start(ap, fmt);
+	vprintf(colorize(fmt), ap);
+	va_end(ap);
+}

src/log.h

@@ -0,0 +1,26 @@
+/*
+ * keyd - A key remapping daemon.
+ *
+ * © 2019 Raheman Vaiya (see also: LICENSE).
+ */
+#ifndef KEYD_LOG_H
+#define KEYD_LOG_H
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+
+#define keyd_log(fmt, ...) _keyd_log(0, fmt, ##__VA_ARGS__);
+
+#define dbg(fmt, ...) _keyd_log(1, "r{DEBUG:} b{%s:%d:} "fmt"\n", __FILE__, __LINE__, ##__VA_ARGS__)
+#define dbg2(fmt, ...) _keyd_log(2, "r{DEBUG:} b{%s:%d:} "fmt"\n", __FILE__, __LINE__, ##__VA_ARGS__)
+
+#define err(fmt, ...) snprintf(errstr, sizeof(errstr), fmt, ##__VA_ARGS__);
+
+void _keyd_log(int level, const char *fmt, ...);
+
+extern int log_level;
+extern int suppress_colours;
+extern char errstr[2048];
+
+#endif

src/monitor.c

@@ -38,14 +38,14 @@ int event_handler(struct event *ev)
 	const char *name;
 
 	case EV_DEV_ADD:
-		printf("device added: %04x:%04x %s (%s)\n",
-		       ev->dev->vendor_id, ev->dev->product_id,
-		       ev->dev->name, ev->dev->path);
+		keyd_log("device added: %04x:%04x %s (%s)\n",
+			  ev->dev->vendor_id, ev->dev->product_id,
+			  ev->dev->name, ev->dev->path);
 		break;
 	case EV_DEV_REMOVE:
-		printf("device removed: %04x:%04x %s (%s)\n",
-		       ev->dev->vendor_id, ev->dev->product_id,
-		       ev->dev->name, ev->dev->path);
+		keyd_log("device removed: %04x:%04x %s (%s)\n",
+			  ev->dev->vendor_id, ev->dev->product_id,
+			  ev->dev->name, ev->dev->path);
 		break;
 	case EV_DEV_EVENT:
 		switch (ev->devev->type) {
@@ -53,13 +53,13 @@ int event_handler(struct event *ev)
 			name = keycode_table[ev->devev->code].name;
 
 			if (time_flag)
-				printf("+%ld ms\t", ev->timestamp - last_time);
+				keyd_log("r{+%ld} ms\t", ev->timestamp - last_time);
 
-			printf("%s\t%04x:%04x\t%s %s\n",
-			       ev->dev->name,
-			       ev->dev->vendor_id,
-			       ev->dev->product_id, name,
-			       ev->devev->pressed ? "down" : "up");
+			keyd_log("%s\t%04x:%04x\t%s %s\n",
+				 ev->dev->name,
+				 ev->dev->vendor_id,
+				 ev->dev->product_id, name,
+				 ev->devev->pressed ? "down" : "up");
 
 			break;
 		default: