diff --git a/README.md b/README.md
index e1ee42c..196ec50 100644
--- a/README.md
+++ b/README.md
@@ -76,6 +76,15 @@ Flags:
   -v, --version                      version for sniffer
 ```
 
+**Shortcuts**
+
+| Keys | Description |
+| ---- | ----------- |
+| <kbd>Space</kbd> | pause refreshing |
+| <kbd>Tab</kbd> | rearrange tables |
+| <kbd>s</kbd> | switch next view mode |
+| <kbd>q</kbd> / <kbd>Ctrl</kbd>+<kbd>C</kbd> | quit |
+
 ## View Mode
 
 ***Bytes Mode:*** display traffic stats in bytes by the Table widget.
diff --git a/cli.go b/cli.go
index 0a7264a..71b4ffe 100644
--- a/cli.go
+++ b/cli.go
@@ -6,7 +6,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
-const version = "v0.1.1"
+const version = "v0.2.0"
 
 func NewApp() *cobra.Command {
 	defaultOpts := DefaultOptions()
diff --git a/conn_darwin.go b/conn_darwin.go
index d6462e0..61e8fdd 100644
--- a/conn_darwin.go
+++ b/conn_darwin.go
@@ -91,16 +91,6 @@ func (lc *lsofConn) getOpenSockets(pids ...int32) (OpenSockets, error) {
 			if err != nil {
 				continue
 			}
-
-			if len(pids) > 0 {
-				pid, err := strconv.Atoi(fields[1])
-				if err != nil {
-					continue
-				}
-				if !set[int32(pid)] {
-					continue
-				}
-			}
 			sockets[LocalSocket{IP: ipport[0], Port: uint16(port), Protocol: ProtoTCP}] = procName
 
 		case "UDP":
diff --git a/pcap.go b/pcap.go
index 7774e2e..51c39cb 100644
--- a/pcap.go
+++ b/pcap.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"strconv"
 	"strings"
 	"sync"
@@ -139,6 +140,10 @@ func (c *PcapClient) getAvailableDevices() error {
 		}
 	}
 
+	if len(c.handlers) == 0 {
+		return errors.New("no available devices found")
+	}
+
 	return nil
 }
 
diff --git a/sniffer.go b/sniffer.go
index cac5ee1..b82a197 100644
--- a/sniffer.go
+++ b/sniffer.go
@@ -85,6 +85,14 @@ func NewSniffer(opts Options) (*Sniffer, error) {
 	}, nil
 }
 
+func (s *Sniffer) SwitchViewMode() {
+	s.opts.ViewMode = (s.opts.ViewMode + 1) % 3
+	s.statsManager = NewStatsManager(s.opts)
+
+	s.ui.Close()
+	s.ui = NewUIComponent(s.opts)
+}
+
 func (s *Sniffer) Start() {
 	events := termui.PollEvents()
 	s.Refresh()
@@ -102,6 +110,8 @@ func (s *Sniffer) Start() {
 			case "<Resize>":
 				payload := e.Payload.(termui.Resize)
 				s.ui.viewer.Resize(payload.Width, payload.Height)
+			case "s", "S":
+				s.SwitchViewMode()
 			case "q", "Q", "<C-c>":
 				return
 			}
@@ -115,9 +125,9 @@ func (s *Sniffer) Start() {
 }
 
 func (s *Sniffer) Close() {
+	s.ui.Close()
 	s.pcapClient.Close()
 	s.dnsResolver.Close()
-	s.ui.Close()
 }
 
 func (s *Sniffer) Refresh() {
diff --git a/ui.go b/ui.go
index ef7c1fb..bcae97b 100644
--- a/ui.go
+++ b/ui.go
@@ -76,7 +76,7 @@ func (u Unit) Ratio() float64 {
 }
 
 func newFooter() *widgets.Paragraph {
-	return newParagraph("Press <Space> to pause, <q>/<Ctrl+C> to exit. Use <Tab> to rearrange tables")
+	return newParagraph("Press <Space> to pause, <q>/<Ctrl+C> to exit, <s> to switch mode. Use <Tab> to rearrange tables")
 }
 
 func newParagraph(text string) *widgets.Paragraph {