all: unified framework for reporting errors/warnings/info messages to stderr/syslog

1 files changed, 69 insertions, 0 deletions

diff --git a/src/reporting.c b/src/reporting.c
new file mode 100644
index 0000000..329d850
--- /dev/null
+++ b/src/reporting.c
@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <syslog.h>
+
+#include "reporting.h"
+
+int verbosity_level = REPORT_WARNING;
+static int syslog_flag = 0;
+/* for converting our own levels to syslog's levels: */
+static int log_levels[5] = { LOG_ALERT, LOG_ERR, LOG_WARNING, LOG_INFO, LOG_DEBUG };
+
+void reporting_init(const char *program_name)
+{
+	openlog(program_name, LOG_PID, LOG_USER);
+	/* reporting to syslog is on by default if stderr is not printed at a terminal */
+	if (!isatty(fileno(stderr)))
+		reporting_use_syslog(1);
+}
+
+void reporting_use_syslog(int flag)
+{
+	syslog_flag = flag;
+}
+
+void reporting_verbosity(int level)
+{
+	verbosity_level = level;
+}
+
+void report_message(int level, const char *format, ...)
+{
+	va_list args;
+	va_start(args, format);
+
+	if(syslog_flag || level == REPORT_ALERT) {
+		syslog(LOG_USER | log_levels[level], format, args);
+		/* va_list can only be used once */
+		va_end(args);
+		va_start(args, format);
+	}
+
+	vfprintf(stderr, format, args);
+	va_end(args);
+}
+
+/* For messages which contain sensitive information, and should not be shown to
+ * all users: */
+void report_private_message(int level, const char *format, ...)
+{
+	if(level <= verbosity_level)
+	{
+		va_list args;
+		va_start(args, format);
+
+		if(syslog_flag || level == REPORT_ALERT) {
+			syslog(LOG_AUTHPRIV | log_levels[level], format, args);
+			/* va_list can only be used once */
+			va_end(args);
+			va_start(args, format);
+		}
+
+		if (getuid() == 0) /* being run by root */
+			vfprintf(stderr, format, args);
+
+		va_end(args);
+	}
+}
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