Improve error message when binding http port.

[darkstat] / err.c

diff --git a/err.c b/err.c
index 0628cd7..358e564 100644 (file)
--- a/err.c
+++ b/err.c
@@ -1,5 +1,5 @@
 /* darkstat 3
- * copyright (c) 2001-2008 Emil Mikulic.
+ * copyright (c) 2001-2011 Emil Mikulic.
  *
  * err.c: BSD-like err() and warn() functions
  *
@@ -16,28 +16,58 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include "darkstat.h"
+#include "cdefs.h"
 #include "err.h"
+#include "opt.h"
 #include "pidfile.h"
+#include "bsd.h" /* for strlcpy */
 
 #include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <syslog.h>
 #include <unistd.h>
 #include <unistd.h>
 
+static void to_syslog(const char *type, const int want_err,
+          const char *format, va_list va) _printflike_(3, 0);
+
+static void
+to_syslog(const char *type, const int want_err,
+          const char *format, va_list va)
+{
+   char buf[512];
+   size_t pos = 0;
+   int saved_errno = errno;
+
+   if (type != NULL) {
+      strlcpy(buf, type, sizeof(buf));
+      pos = strlen(buf);
+   }
+   vsnprintf(buf+pos, sizeof(buf)-pos, format, va);
+   if (want_err) {
+      strlcat(buf, ": ", sizeof(buf));
+      strlcat(buf, strerror(saved_errno), sizeof(buf));
+   }
+   syslog(LOG_DEBUG, "%s", buf);
+}
+
 void
 err(const int code, const char *format, ...)
 {
    va_list va;
 
-   fprintf(stderr, "%5d: error: ", (int)getpid());
    va_start(va, format);
-   vfprintf(stderr, format, va);
+   if (opt_want_syslog)
+      to_syslog("ERROR: ", 1, format, va);
+   else {
+      fprintf(stderr, "%5d: error: ", (int)getpid());
+      vfprintf(stderr, format, va);
+      fprintf(stderr, ": %s\n", strerror(errno));
+   }
    va_end(va);
-   fprintf(stderr, ": %s\n", strerror(errno));
    pidfile_unlink();
    exit(code);
 }
@@ -47,11 +77,15 @@ errx(const int code, const char *format, ...)
 {
    va_list va;
 
-   fprintf(stderr, "%5d: error: ", (int)getpid());
    va_start(va, format);
-   vfprintf(stderr, format, va);
+   if (opt_want_syslog)
+      to_syslog("ERROR: ", 0, format, va);
+   else {
+      fprintf(stderr, "%5d: error: ", (int)getpid());
+      vfprintf(stderr, format, va);
+      fprintf(stderr, "\n");
+   }
    va_end(va);
-   fprintf(stderr, "\n");
    pidfile_unlink();
    exit(code);
 }
@@ -61,11 +95,15 @@ warn(const char *format, ...)
 {
    va_list va;
 
-   fprintf(stderr, "%5d: warning: ", (int)getpid());
    va_start(va, format);
-   vfprintf(stderr, format, va);
+   if (opt_want_syslog)
+      to_syslog("WARNING: ", 1, format, va);
+   else {
+      fprintf(stderr, "%5d: warning: ", (int)getpid());
+      vfprintf(stderr, format, va);
+      fprintf(stderr, ": %s\n", strerror(errno));
+   }
    va_end(va);
-   fprintf(stderr, ": %s\n", strerror(errno));
 }
 
 void
@@ -73,11 +111,15 @@ warnx(const char *format, ...)
 {
    va_list va;
 
-   fprintf(stderr, "%5d: warning: ", (int)getpid());
    va_start(va, format);
-   vfprintf(stderr, format, va);
+   if (opt_want_syslog)
+      to_syslog("WARNING: ", 0, format, va);
+   else {
+      fprintf(stderr, "%5d: warning: ", (int)getpid());
+      vfprintf(stderr, format, va);
+      fprintf(stderr, "\n");
+   }
    va_end(va);
-   fprintf(stderr, "\n");
 }
 
 /* We interlock verbosef() between processes by using a pipe with a single
@@ -127,21 +169,23 @@ unlock(void)
    }
 }
 
-int want_verbose = 0;
-
 void
 verbosef(const char *format, ...)
 {
    va_list va;
 
-   if (!want_verbose) return;
-   lock();
-   fprintf(stderr, "darkstat (%05d): ", (int)getpid());
+   if (!opt_want_verbose) return;
    va_start(va, format);
-   vfprintf(stderr, format, va);
+   if (opt_want_syslog)
+      to_syslog(NULL, 0, format, va);
+   else {
+      lock();
+      fprintf(stderr, "darkstat (%05d): ", (int)getpid());
+      vfprintf(stderr, format, va);
+      fprintf(stderr, "\n");
+      unlock();
+   }
    va_end(va);
-   fprintf(stderr, "\n");
-   unlock();
 }
 
 void