Index: ext/libicpf/src/log.cpp
===================================================================
diff -u -r9a6c943d8b2737422c3652980c8cce2c03679422 -raea5c1302fae74ec41e9d7649f8b8b2b8138aee1
--- ext/libicpf/src/log.cpp	(.../log.cpp)	(revision 9a6c943d8b2737422c3652980c8cce2c03679422)
+++ ext/libicpf/src/log.cpp	(.../log.cpp)	(revision aea5c1302fae74ec41e9d7649f8b8b2b8138aee1)
@@ -37,7 +37,10 @@
 #endif
 
 #ifdef WIN32
-	#define vsnprintf _vsnprintf;
+	#undef vsnprintf
+	#define vsnprintf _vsnprintf
+	#undef snprintf
+	#define snprintf _snprintf
 #endif
 
 BEGIN_ICPF_NAMESPACE
@@ -528,4 +531,95 @@
 	va_end(va);
 }
 
+/** Logs a formatted error message to a log file(also outputs to stderr).
+ *  As an addition the first string %err is replaced with a given error 
+ *  followed by the error description (system-based).
+ * \param[in] pszStr - format string for the given parameters
+ * \param[in] iSysErr - system error to be shown
+ */
+void log_file::logerr(const char_t* pszStr, int iSysErr, ...)
+{
+	char_t szNewFmt[2048];
+	if (prepare_fmt(pszStr, iSysErr, szNewFmt))
+	{
+		va_list va;
+		va_start(va, iSysErr);
+		logv(LT_ERROR, false, szNewFmt, va);
+		va_end(va);
+	}
+	else
+	{
+		va_list va;
+		va_start(va, iSysErr);
+		logv(LT_ERROR, false, pszStr, va);
+		va_end(va);
+	}
+}
+
+/** Logs a formatted error message to a log file(also outputs to stderr).
+ *  As an addition the first string %err is replaced with a given error 
+ *  followed by the error description (system-based).
+ *  This function differ from logerr() with logging the output string
+ *  also to the stderr.
+ * \param[in] pszStr - format string for the given parameters
+ * \param[in] iSysErr - system error to be shown
+ */
+void log_file::logerrs(const char_t* pszStr, int iSysErr, ...)
+{
+	char_t szNewFmt[2048];
+	if (prepare_fmt(pszStr, iSysErr, szNewFmt))
+	{
+		va_list va;
+		va_start(va, iSysErr);
+		logv(LT_ERROR, true, szNewFmt, va);
+		va_end(va);
+	}
+	else
+	{
+		va_list va;
+		va_start(va, iSysErr);
+		logv(LT_ERROR, true, pszStr, va);
+		va_end(va);
+	}
+}
+
+/** Function prepares a format string with error number and an error message
+ *  for use with logerr() and logerrs() functions.
+ * \param[in] pszStr - input format string (%err will be replaced with a 0x%lx (error message)
+ * \param[in] iSysError - system error to parse
+ * \param[out] pszOut - pointer to a buffer that will receive the data (must be 2048 bytes in size)
+ * \return If the %err string was found and replaced within a given format string.
+ */
+bool log_file::prepare_fmt(const char_t* pszStr, int iSysErr, char_t* pszOut)
+{
+	// find the %err in pszStr
+	char_t* pszFnd=strstr(pszStr, "%err");
+	if (pszFnd)
+	{
+		// find an error description for the error
+		char_t* pszErrDesc=NULL;
+#ifdef _WIN32
+		char_t szErrDesc[512];
+		FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, (DWORD)iSysErr, 0, szErrDesc, 512, NULL);
+		pszErrDesc=szErrDesc;
+#else
+		pszErrDesc=strerror(iSysErr);
+#endif
+
+		// format a string with err no and desc
+		char_t szError[1024];
+		snprintf(szError, 1024, "0x%lx (%s)", iSysErr, pszErrDesc);
+
+		// replace %err with the new data
+		pszOut[0]='\0';
+		strncat(pszOut, pszStr, pszFnd-pszStr);
+		strcat(pszOut, szError);
+		strcat(pszOut, pszFnd+4);
+
+		return true;
+	}
+	else
+		return false;
+}
+
 END_ICPF_NAMESPACE
Index: ext/libicpf/src/log.h
===================================================================
diff -u -r01f412dddb725bcd82c0dce8755af7f113a101d8 -raea5c1302fae74ec41e9d7649f8b8b2b8138aee1
--- ext/libicpf/src/log.h	(.../log.h)	(revision 01f412dddb725bcd82c0dce8755af7f113a101d8)
+++ ext/libicpf/src/log.h	(.../log.h)	(revision aea5c1302fae74ec41e9d7649f8b8b2b8138aee1)
@@ -141,6 +141,9 @@
 
 	void loge(const char_t* pszStr, ...);		///< Logs an error message with formatting
 	void loges(const char_t* pszStr, ...);	///< Logs an error message with formatting(also prints to stderr)
+
+	void logerr(const char_t* pszStr, int iSysErr, ...);	///< Logs an error message with system error number and error description
+	void logerrs(const char_t* pszStr, int iSysErr, ...);	///< Logs an error message with system error number and error description (also prints to stderr)
 /**@}*/
 
 	/// Gets the global instance of the log file
@@ -155,6 +158,10 @@
 	bool truncate(int_t iAdd);
 	/// Returns the size of a log file
 	int_t size();
+
+private:
+	/// Prepares a new format string for logerr(s) functions
+	bool prepare_fmt(const char_t* pszStr, int iSysErr, char_t* pszOut);
 	
 public:
 	char_t* m_pszPath;	///< Path to the log file