Implemented syslog output. For now, it will be put into /tmp (i.e. the tests

won't clobber your existing syslog).
The time stamp is currently #ifdef'd out. We might think about adding some
prefs; the facility could also only printed for kernel messages (like in
Be's implementation).


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@5343 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/syslog_daemon/syslog_output.cpp

@@ -6,13 +6,151 @@
 
 #include "syslog_output.h"
 
+#include <FindDirectory.h>
+#include <Path.h>
+
+#include <syslog.h>
 #include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+
+static const size_t kMaxLogSize = 524288;	// 512kB
+
+static const char *kFacilities[] = {
+	"KERN", "USER", "MAIL", "DAEMON",
+	"AUTH", "SYSLOGD", "LPR", "NEWS",
+	"UUCP", "CRON", "AUTHPRIV",
+	"", "", "", "", "",
+	"LOCAL0", "LOCAL1", "LOCAL2", "LOCAL3",
+	"LOCAL4", "LOCAL5", "LOCAL6", "LOCAL7",
+	NULL
+};
+static const int32 kNumFacilities = 24;
+
+int sLog = -1;
+char sLastMessage[1024];
+thread_id sLastThread;
+int32 sRepeatCount;
+
+
+static status_t
+prepare_output()
+{
+	bool needNew = true;
+	bool tooLarge = false;
+
+	if (sLog > 0) {
+		// check file size
+		struct stat stat;
+		if (fstat(sLog, &stat) == 0) {
+			if (stat.st_size < kMaxLogSize)
+				needNew = false;
+			else
+				tooLarge = true;
+		}
+	}
+
+	if (needNew) {
+		// get path
+		BPath base;
+		find_directory(/*B_COMMON_LOG_DIRECTORY*/B_COMMON_TEMP_DIRECTORY, &base);
+			// ToDo: change to correct "which" parameter!
+
+		BPath syslog(base);
+		syslog.Append("syslog");
+
+		// move old file if it already exists
+		if (tooLarge) {
+			base.Append("syslog.old");
+			rename(syslog.Path(), base.Path());
+
+			// ToDo: remove old file if space on device is tight?
+		}
+
+		// open file
+		sLog = open(syslog.Path(), O_APPEND | O_CREAT | O_WRONLY, 644);
+	}
+
+	return sLog >= 0 ? B_OK : B_ERROR;
+}
+
+
+static status_t
+write_to_log(const char *buffer, int32 length)
+{
+	if (sRepeatCount > 0) {
+		char repeat[64];
+		ssize_t size = snprintf(repeat, sizeof(repeat),
+							"Last message repeated %ld time%s\n", sRepeatCount,
+							sRepeatCount > 1 ? "s" : "");
+		sRepeatCount = 0;
+		if (write(sLog, repeat, strlen(repeat)) < size)
+			return B_ERROR;
+	}
+
+	if (write(sLog, buffer, length) < length)
+		return B_ERROR;
+
+	return B_OK;
+}
 
 
 static void
 syslog_output(syslog_message &message)
 {
-	printf("'%s'[%ld]: %s\n", message.ident, message.from, message.message);
+	// did we get this message already?
+	if (message.from == sLastThread
+		&& !strncmp(message.message, sLastMessage, sizeof(sLastMessage))) {
+		sRepeatCount++;
+		return;
+	}
+
+	char buffer[4096];
+
+#if 0
+	// parse & nicely print the time stamp from the message
+	struct tm when;
+	localtime_r(&message.when, &when);
+	int32 pos = strftime(buffer, sizeof(buffer), "%b %d, %H:%M:%S ", &when);
+#else
+	int32 pos = 0;
+#endif
+
+	// add facility
+	int facility = SYSLOG_FACILITY_INDEX(message.priority);
+	if (facility >= kNumFacilities)
+		facility = SYSLOG_FACILITY_INDEX(LOG_USER);
+	pos += snprintf(buffer + pos, sizeof(buffer) - pos, "%s", kFacilities[facility]);
+
+	// add ident/thread ID
+	if (message.ident[0] == '\0') {
+		// ToDo: find out team name?
+	} else
+		pos += snprintf(buffer + pos, sizeof(buffer) - pos, " '%s'", message.ident);
+
+	if (message.options & LOG_PID)
+		pos += snprintf(buffer + pos, sizeof(buffer) - pos, "[%ld]", message.from);
+
+	// add message itself
+	int32 length = pos + snprintf(buffer + pos, sizeof(buffer) - pos, ": %s\n", message.message);
+
+	// ToDo: be less lazy about it - there is virtually no reason to truncate the message
+	if (strlen(message.message) > sizeof(buffer) - pos - 1)
+		strcpy(&buffer[sizeof(buffer) - 8], "<TRUNC>\n");
+
+	// dump message
+
+	if (prepare_output() < B_OK
+		|| write_to_log(buffer, length) < B_OK) {
+		// cannot write to syslog!
+		fputs(buffer, stderr);
+	}
+
+	// save this message to suppress repeated messages
+	strlcpy(sLastMessage, message.message, sizeof(sLastMessage));
+	sLastThread = message.from;
 }