syslogd: add option to suppress logging of messages lower than level N (-n N)

2 files changed, 18 insertions, 5 deletions

diff --git a/include/usage.h b/include/usage.h
index 543befca3..1da436ad4 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2780,7 +2780,8 @@ USE_FEATURE_START_STOP_DAEMON_FANCY( \
         "\t-m MIN\t\tMinutes between MARK lines (default=20, 0=off)\n" \
         "\t-n\t\tRun as a foreground process\n" \
         "\t-O FILE\t\tUse an alternate log file (default=/var/log/messages)\n" \
-        "\t-S\t\tMake logging output smaller." \
+        "\t-l n\tSets the local log level of messages to n\n" \
+        "\t-S\t\tMake logging output smaller" \
         USE_FEATURE_ROTATE_LOGFILE( \
         "\n\t-s SIZE\t\tMax size (KB) before rotate (default=200KB, 0=off)\n" \
         "\t-b NUM\t\tNumber of rotated logs to keep (default=1, max=99, 0=purge)") \
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index 9a5a04adb..a257e740e 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -42,6 +42,9 @@ static int logFileRotate = 1;
 /* interval between marks in seconds */
 static int MarkInterval = 20 * 60;
 
+/* level of messages to be locally logged */
+static int logLevel = 8;
+
 /* localhost's name */
 static char LocalHostName[64];
 
@@ -413,10 +416,12 @@ retry:
 #endif
         {
                 /* now spew out the message to wherever it is supposed to go */
-                if (opts & SYSLOG_OPT_small)
-                        message("%s %s\n", timestamp, msg);
-                else
-                        message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
+                if (pri == 0 || LOG_PRI(pri) < logLevel) {
+                        if (opts & SYSLOG_OPT_small)
+                                message("%s %s\n", timestamp, msg);
+                        else
+                                message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
+                }
         }
 }
 
@@ -581,6 +586,13 @@ int syslogd_main(int argc, char **argv)
                 case 'O':
                         logFilePath = optarg;
                         break;
+                case 'l':
+                        logLevel = atoi(optarg);
+                        /* Valid levels are between 1 and 8 */
+                        if (logLevel < 1 || logLevel > 8) {
+                                bb_show_usage();
+                        }
+                        break;
 #ifdef CONFIG_FEATURE_ROTATE_LOGFILE
                 case 's':
                         logFileSize = atoi(optarg) * 1024;