log: enhance logging output

Append the current date in front of the log line. Display the
priority. Add some colors when logging on a TTY.

diff --git a/src/log.c b/src/log.c
index 02a094a45cbb8e528169af5ceb12b6c30be2084a..df5fd80f4e2a463bdcf3d458d9b4d820d39a0a4d 100644 (file)
--- a/src/log.c
+++ b/src/log.c
@@ -18,6 +18,7 @@
  */
 
 #define _GNU_SOURCE
+#include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
@@ -64,6 +65,50 @@ logit(int pri, const char *fmt, ...)
        va_end(ap);
 }
 
+static char *
+date()
+{
+       /* Return the current date as incomplete ISO 8601 (2012-12-12T16:13:30) */
+       static char date[] = "2012-12-12T16:13:30";
+       time_t t = time(NULL);
+       struct tm *tmp = localtime(&t);
+       strftime(date, sizeof(date), "%Y-%m-%dT%H:%M:%S", tmp);
+       return date;
+}
+
+static const char *
+translate(int fd, int priority)
+{
+       /* Translate a syslog priority to a string. With colors if the output is a terminal. */
+       int tty = isatty(fd);
+       switch (tty) {
+       case 1:
+               switch (priority) {
+               case LOG_EMERG:   return "\033[1;37;41m[EMRG]\033[0m";
+               case LOG_ALERT:   return "\033[1;37;41m[ALRT]\033[0m";
+               case LOG_CRIT:    return "\033[1;37;41m[CRIT]\033[0m";
+               case LOG_ERR:     return "\033[1;31m[ ERR]\033[0m";
+               case LOG_WARNING: return "\033[1;33m[WARN]\033[0m";
+               case LOG_NOTICE:  return "\033[1;34m[NOTI]\033[0m";
+               case LOG_INFO:    return "\033[1;34m[INFO]\033[0m";
+               case LOG_DEBUG:   return "\033[1;30m[ DBG]\033[0m";
+               }
+               break;
+       default:
+               switch (priority) {
+               case LOG_EMERG:   return "[EMRG]";
+               case LOG_ALERT:   return "[ALRT]";
+               case LOG_CRIT:    return "[CRIT]";
+               case LOG_ERR:     return "[ ERR]";
+               case LOG_WARNING: return "[WARN]";
+               case LOG_NOTICE:  return "[NOTI]";
+               case LOG_INFO:    return "[INFO]";
+               case LOG_DEBUG:   return "[ DBG]";
+               }
+       }
+       return "[UNKN]";
+}
+
 static void
 vlog(int pri, const char *fmt, va_list ap)
 {
@@ -78,7 +123,10 @@ vlog(int pri, const char *fmt, va_list ap)
        if (debug || logh) {
                char *nfmt;
                /* best effort in out of mem situations */
-               if (asprintf(&nfmt, "%s\n", fmt) == -1) {
+               if (asprintf(&nfmt, "%s %s %s\n",
+                       date(),
+                       translate(STDERR_FILENO, pri),
+                       fmt) == -1) {
                        vfprintf(stderr, fmt, ap);
                        fprintf(stderr, "\n");
                } else {
@@ -99,16 +147,16 @@ log_warn(const char *emsg, ...)
 
        /* best effort to even work in out of memory situations */
        if (emsg == NULL)
-               logit(LOG_CRIT, "%s", strerror(errno));
+               logit(LOG_WARNING, "%s", strerror(errno));
        else {
                va_start(ap, emsg);
 
                if (asprintf(&nfmt, "%s: %s", emsg, strerror(errno)) == -1) {
                        /* we tried it... */
-                       vlog(LOG_CRIT, emsg, ap);
-                       logit(LOG_CRIT, "%s", strerror(errno));
+                       vlog(LOG_WARNING, emsg, ap);
+                       logit(LOG_WARNING, "%s", strerror(errno));
                } else {
-                       vlog(LOG_CRIT, nfmt, ap);
+                       vlog(LOG_WARNING, nfmt, ap);
                        free(nfmt);
                }
                va_end(ap);
@@ -121,7 +169,7 @@ log_warnx(const char *emsg, ...)
        va_list  ap;
 
        va_start(ap, emsg);
-       vlog(LOG_CRIT, emsg, ap);
+       vlog(LOG_WARNING, emsg, ap);
        va_end(ap);
 }
 
@@ -130,9 +178,11 @@ log_info(const char *emsg, ...)
 {
        va_list  ap;
 
-       va_start(ap, emsg);
-       vlog(LOG_INFO, emsg, ap);
-       va_end(ap);
+       if (debug > 1 || logh) {
+               va_start(ap, emsg);
+               vlog(LOG_INFO, emsg, ap);
+               va_end(ap);
+       }
 }
 
 void
@@ -140,7 +190,7 @@ log_debug(const char *emsg, ...)
 {
        va_list  ap;
 
-       if (debug > 1 || logh) {
+       if (debug > 2 || logh) {
                va_start(ap, emsg);
                vlog(LOG_DEBUG, emsg, ap);
                va_end(ap);