1 files changed, 91 insertions, 0 deletions
diff --git a/util/log.c b/util/log.c
new file mode 100644
index 00000000..3ef5f484
--- /dev/null
+++ b/util/log.c
@@ -0,0 +1,91 @@
+#define _POSIX_C_SOURCE 199506L
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <wlr/util/log.h>
+
+static bool colored = true;
+static enum wlr_log_importance log_importance = WLR_ERROR;
+
+static const char *verbosity_colors[] = {
+	[WLR_SILENT] = "",
+	[WLR_ERROR ] = "\x1B[1;31m",
+	[WLR_INFO  ] = "\x1B[1;34m",
+	[WLR_DEBUG ] = "\x1B[1;30m",
+};
+
+static void log_stderr(enum wlr_log_importance verbosity, const char *fmt,
+		va_list args) {
+	if (verbosity > log_importance) {
+		return;
+	}
+	// prefix the time to the log message
+	struct tm result;
+	time_t t = time(NULL);
+	struct tm *tm_info = localtime_r(&t, &result);
+	char buffer[26];
+
+	// generate time prefix
+	strftime(buffer, sizeof(buffer), "%F %T - ", tm_info);
+	fprintf(stderr, "%s", buffer);
+
+	unsigned c = (verbosity < WLR_LOG_IMPORTANCE_LAST) ? verbosity : WLR_LOG_IMPORTANCE_LAST - 1;
+
+	if (colored && isatty(STDERR_FILENO)) {
+		fprintf(stderr, "%s", verbosity_colors[c]);
+	}
+
+	vfprintf(stderr, fmt, args);
+
+	if (colored && isatty(STDERR_FILENO)) {
+		fprintf(stderr, "\x1B[0m");
+	}
+	fprintf(stderr, "\n");
+}
+
+static wlr_log_func_t log_callback = log_stderr;
+
+void wlr_log_init(enum wlr_log_importance verbosity, wlr_log_func_t callback) {
+	if (verbosity < WLR_LOG_IMPORTANCE_LAST) {
+		log_importance = verbosity;
+	}
+	if (callback) {
+		log_callback = callback;
+	}
+}
+
+void _wlr_vlog(enum wlr_log_importance verbosity, const char *fmt, va_list args) {
+	log_callback(verbosity, fmt, args);
+}
+
+void _wlr_log(enum wlr_log_importance verbosity, const char *fmt, ...) {
+	va_list args;
+	va_start(args, fmt);
+	log_callback(verbosity, fmt, args);
+	va_end(args);
+}
+
+// strips the path prefix from filepath
+// will try to strip WLR_SRC_DIR as well as a relative src dir
+// e.g. '/src/build/wlroots/backend/wayland/backend.c' and
+// '../backend/wayland/backend.c' will both be stripped to
+// 'backend/wayland/backend.c'
+const char *_wlr_strip_path(const char *filepath) {
+	static int srclen = sizeof(WLR_SRC_DIR);
+	if (strstr(filepath, WLR_SRC_DIR) == filepath) {
+		filepath += srclen;
+	} else if (*filepath == '.') {
+		while (*filepath == '.' || *filepath == '/') {
+			++filepath;
+		}
+	}
+	return filepath;
+}
+
+enum wlr_log_importance wlr_log_get_verbosity(void) {
+	return log_importance;
+}