diff --git a/dhcp/dhcp.go b/dhcp/dhcp.go
index 1391822..4eddd14 100644
--- a/dhcp/dhcp.go
+++ b/dhcp/dhcp.go
@@ -46,7 +46,7 @@ type dhcpDiscover struct {
 func DiscoverDHCP() {
 	err := sendDHCPDiscovery()
 	if err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: DHCP Matcher %v", err))
+		logging.Logger().Errorf("Discovery: DHCP Matcher %v", err)
 		return
 	}
 	recvDHCPOffer()
@@ -101,23 +101,23 @@ func recvDHCPOffer() {
 		Port: 68,
 	})
 	if err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: DHCP Matcher %v", err))
+		logging.Logger().Errorf("Discovery: DHCP Matcher %v", err)
 		return
 	}
 	err = socket.SetDeadline(time.Now().Add(3 * time.Second))
 	if err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: DHCP Matcher %v", err))
+		logging.Logger().Errorf("Discovery: DHCP Matcher %v", err)
 		return
 	}
 
 	buf := make([]byte, 4096)
 	n, _, err := socket.ReadFromUDP(buf)
 	if err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: DHCP Matcher %v", err))
+		logging.Logger().Errorf("Discovery: DHCP Matcher %v", err)
 		return
 	}
 	if n <= 0 {
-		logging.Logger().Error(fmt.Sprintf("Discovery: DHCP Matcher has no DHCP offer."))
+		logging.Logger().Errorf("Discovery: DHCP Matcher has no DHCP offer.")
 		return
 	}
 
@@ -126,11 +126,11 @@ func recvDHCPOffer() {
 	reader := new(bytes.Buffer)
 	reader.Write(buf)
 	if err := binary.Read(reader, binary.BigEndian, &offer); err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: DHCP Matcher %v", err))
+		logging.Logger().Errorf("Discovery: DHCP Matcher %v", err)
 		return
 	}
 	if offer.MagicCookie != MAGIC_COOKIE {
-		logging.Logger().Error(fmt.Sprintf("Discovery: DHCP Matcher is not a DHCP packet."))
+		logging.Logger().Errorf("Discovery: DHCP Matcher is not a DHCP packet.")
 		return
 	}
 
@@ -143,12 +143,12 @@ func recvDHCPOffer() {
 
 		if v == OPT_CODE_SUBNET_MASK && r.Next(1)[0] == 4 {
 			ipStr := byteToIpString(r.Next(4))
-			logging.Logger().Info(fmt.Sprintf("Discovery: DHCP Matcher SUBNET MASK: %s", ipStr))
+			logging.Logger().Infof("Discovery: DHCP Matcher SUBNET MASK: %s", ipStr)
 		}
 
 		if v == OPT_CODE_ROUTER && r.Next(1)[0] == 4 {
 			ipStr := byteToIpString(r.Next(4))
-			logging.Logger().Info(fmt.Sprintf("Discovery: DHCP Matcher ROUTER: %s", ipStr))
+			logging.Logger().Infof("Discovery: DHCP Matcher ROUTER: %s", ipStr)
 		}
 
 		if v == OPT_CODE_DNS {
@@ -161,12 +161,12 @@ func recvDHCPOffer() {
 				ipStr = byteToIpString(r.Next(4))
 				dns = append(dns, ipStr)
 			}
-			logging.Logger().Info(fmt.Sprintf("Discovery: DHCP Matcher DNS: %s", dns))
+			logging.Logger().Infof("Discovery: DHCP Matcher DNS: %s", dns)
 		}
 
 		if v == OPT_CODE_SERVER_IDENTIFIER && r.Next(1)[0] == 4 {
 			ipStr := byteToIpString(r.Next(4))
-			logging.Logger().Info(fmt.Sprintf("Discovery: DHCP Matcher DHCP SERVER: %s", ipStr))
+			logging.Logger().Infof("Discovery: DHCP Matcher DHCP SERVER: %s", ipStr)
 		}
 	}
 	logging.Logger().Sync()
diff --git a/ftp/ftp.go b/ftp/ftp.go
index b1aa2fb..97dd0bc 100644
--- a/ftp/ftp.go
+++ b/ftp/ftp.go
@@ -56,7 +56,7 @@ func (ftp *FTPMatcher) Match(info cnsm.MatchInfo, index int, packet *cnsm.Packet
 	result := false
 
 	if packet == nil || packet.Buffer == nil || packet.Len == 0 {
-		logging.Logger().Error(fmt.Sprintf("Discovery: FTP Matcher Packet nil"))
+		logging.Logger().Errorf("Discovery: FTP Matcher Packet nil")
 		return result
 	}
 
@@ -105,7 +105,7 @@ func (ftp *FTPMatcher) Match(info cnsm.MatchInfo, index int, packet *cnsm.Packet
 		if isfs && err == nil {
 			ftp.isFtps = isfs
 		} else if err != nil {
-			logging.Logger().Warn(fmt.Sprintf("Discovery: FTP Matcher Check Error %v", err))
+			logging.Logger().Warnf("Discovery: FTP Matcher Check Error %v", err)
 		}
 	}
 
diff --git a/ftp/ftps.go b/ftp/ftps.go
index a10f5aa..afc67d6 100644
--- a/ftp/ftps.go
+++ b/ftp/ftps.go
@@ -40,12 +40,12 @@ func (fs *FTPS) quit() (err error) {
 
 func (fs *FTPS) cmd(expects string, cmd string) (line string, err error) {
 	if err = fs.send(cmd); err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: FTPS Matcher cmd send error %v", err))
+		logging.Logger().Errorf("Discovery: FTPS Matcher cmd send error %v", err)
 		return "", err
 	}
 
 	if line, err = fs.receive(); err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: FTPS Matcher cmd receive error %v", err))
+		logging.Logger().Errorf("Discovery: FTPS Matcher cmd receive error %v", err)
 		return line, err
 	}
 
@@ -132,7 +132,7 @@ func (fs *FTPS) NewFTPSConnect(addr string) (*FTPS, error) {
 	var conn net.Conn
 
 	if conn, err = net.Dial("tcp", addr); err != nil {
-		logging.Logger().Error(fmt.Sprintf("Discovery: FTPS Matcher Socket Fail %v", err))
+		logging.Logger().Errorf("Discovery: FTPS Matcher Socket Fail %v", err)
 		return nil, err
 	}