diff --git a/process.go b/process.go
index 30e9e31..ee1ad06 100644
--- a/process.go
+++ b/process.go
@@ -1,4 +1,4 @@
-// Copyright 2017 CoreSwitch
+// Copyright 2017 CoreSwitch.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,28 +15,60 @@
 package process
 
 import (
+	"fmt"
+	"os"
+	"os/exec"
 	"sync"
+	"time"
+
+	"golang.org/x/net/context"
 )
 
 type Process struct {
-	Name string
-	Vrf  string
-	Args []string
-	File string
+	Name       string
+	Vrf        string
+	Args       []string
+	File       string
+	ErrLookup  string
+	ErrStart   string
+	ErrWait    string
+	ExitFunc   func()
+	State      int
+	Cmd        *exec.Cmd
+	StartTimer int
+	RetryTimer int
 }
 
-type ProcessList map[string]*Process
+type ProcessSlice []*Process
 
-var (
-	ProcessVrfMap = map[string]*ProcessList{}
-	ProcessMutex  sync.RWMutex
+const (
+	PROCESS_STARTING = iota
+	PROCESS_RUNNING
+	PROCESS_RETRY
+	PROCESS_EXIT_CALLED
+	PROCESS_STOP_WAIT
+	PROCESS_STOP
 )
 
-func NewProcess(name string, vrf string, args ...string) *Process {
+var (
+	ProcessList  = ProcessSlice{}
+	ProcessMutex sync.RWMutex
+)
+
+var ProcessStateStr = map[int]string{
+	PROCESS_STARTING:    "Starting",
+	PROCESS_RUNNING:     "Running",
+	PROCESS_RETRY:       "Retry",
+	PROCESS_EXIT_CALLED: "Exit Called",
+	PROCESS_STOP_WAIT:   "Stop Wait",
+	PROCESS_STOP:        "Stop",
+}
+
+func NewProcess(name string, args ...string) *Process {
 	proc := &Process{
-		Name: name,
-		Vrf:  vrf,
-		Args: []string(args),
+		Name:       name,
+		Args:       []string(args),
+		RetryTimer: 1,
 	}
 	return proc
 }
@@ -44,25 +76,169 @@ func NewProcess(name string, vrf string, args ...string) *Process {
 func ProcessRegister(proc *Process) {
 	ProcessMutex.Lock()
 	defer ProcessMutex.Unlock()
+
+	ProcessList = append(ProcessList, proc)
+	proc.Start()
 }
 
 func ProcessUnregister(proc *Process) {
 	ProcessMutex.Lock()
 	defer ProcessMutex.Unlock()
+
+	proc.Stop()
+
+	procList := ProcessSlice{}
+	for _, p := range ProcessList {
+		if p != proc {
+			procList = append(procList, p)
+		}
+	}
+	ProcessList = procList
 }
 
-func ProcessUnregisterByCommand(name string) {
+func ProcessCount() int {
 	ProcessMutex.Lock()
 	defer ProcessMutex.Unlock()
+
+	return len(ProcessList)
 }
 
-func ProcessUnregisterByVrf() {
+func ProcessStart(index int) {
 	ProcessMutex.Lock()
 	defer ProcessMutex.Unlock()
+
+	if index <= 0 {
+		return
+	}
+	if len(ProcessList) < index {
+		return
+	}
+	proc := ProcessList[index-1]
+	if proc == nil {
+		return
+	}
+	proc.Start()
+}
+
+func ProcessStop(index int) {
+	ProcessMutex.Lock()
+	defer ProcessMutex.Unlock()
+
+	if index <= 0 {
+		return
+	}
+	if len(ProcessList) < index {
+		return
+	}
+	proc := ProcessList[index-1]
+	if proc == nil {
+		return
+	}
+	proc.Stop()
 }
 
 func (proc *Process) Start() {
+	if proc.ExitFunc != nil {
+		return
+	}
+
+	proc.State = PROCESS_STOP
+	binary, err := exec.LookPath(proc.Name)
+	if err != nil {
+		proc.ErrLookup = err.Error()
+		return
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	var wg sync.WaitGroup
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+
+		for {
+			proc.State = PROCESS_STARTING
+			if proc.File != "" {
+				os.OpenFile(proc.File, os.O_RDWR|os.O_CREATE, 0644)
+			}
+
+			cmd := exec.CommandContext(ctx, binary, proc.Args...)
+
+			env := os.Environ()
+			if proc.Vrf != "" {
+				env = append(env, fmt.Sprintf("VRF=%s", proc.Vrf))
+				env = append(env, "LD_PRELOAD=/usr/bin/vrf_socket.so")
+			}
+			cmd.Env = env
+			proc.Cmd = cmd
+
+			if proc.StartTimer != 0 {
+				time.Sleep(time.Duration(proc.StartTimer) * time.Second)
+			}
+
+			// fmt.Println("process:", cmd.Path, cmd.Args)
+			err = cmd.Start()
+			if err != nil {
+				proc.ErrStart = err.Error()
+			}
+
+			proc.State = PROCESS_RUNNING
+			err = cmd.Wait()
+			if err != nil {
+				proc.ErrWait = err.Error()
+			}
+
+			proc.State = PROCESS_RETRY
+			retryTimer := time.NewTimer(time.Duration(proc.RetryTimer) * time.Second)
+			select {
+			case <-retryTimer.C:
+			case <-done:
+				retryTimer.Stop()
+				return
+			}
+		}
+	}()
+
+	proc.ExitFunc = func() {
+		proc.State = PROCESS_EXIT_CALLED
+		close(done)
+		cancel()
+		proc.State = PROCESS_STOP_WAIT
+		wg.Wait()
+		proc.State = PROCESS_STOP
+	}
 }
 
 func (proc *Process) Stop() {
+	if proc.ExitFunc != nil {
+		proc.ExitFunc()
+		proc.ExitFunc = nil
+	}
+}
+
+func ProcessListShow() string {
+	str := ""
+	for pos, proc := range ProcessList {
+		str += fmt.Sprintf("%d %s", pos+1, proc.Name)
+		if proc.Vrf != "" {
+			str += fmt.Sprintf("@%s", proc.Vrf)
+		}
+		str += fmt.Sprintf(": %s", ProcessStateStr[proc.State])
+		if proc.State == PROCESS_RUNNING && proc.Cmd != nil && proc.Cmd.Process != nil {
+			str += fmt.Sprintf(" (pid %d)", proc.Cmd.Process.Pid)
+		}
+		str += "\n"
+		if proc.ErrLookup != "" {
+			str += fmt.Sprintf("  Last Lookup Error: %s\n", proc.ErrLookup)
+		}
+		if proc.ErrStart != "" {
+			str += fmt.Sprintf("  Last Start Error: %s\n", proc.ErrStart)
+		}
+		if proc.ErrWait != "" {
+			str += fmt.Sprintf("  Last Wait Error: %s\n", proc.ErrWait)
+		}
+		str += fmt.Sprintf("  %s\n", proc.Args)
+	}
+	return str
 }
diff --git a/process_test.go b/process_test.go
index a82a5d7..bd859d1 100644
--- a/process_test.go
+++ b/process_test.go
@@ -15,11 +15,24 @@
 package process
 
 import (
+	"fmt"
 	"testing"
 )
 
 func TestProcessStart(t *testing.T) {
 	args := []string{"-d", "-f"}
-	proc := NewProcess("dhcp", "", args...)
-	ProcessRegister(proc)
+	proc1 := NewProcess("dhcp", args...)
+	ProcessRegister(proc1)
+	proc2 := NewProcess("dhcp", args...)
+	ProcessRegister(proc2)
+	fmt.Println(ProcessCount())
+
+	ProcessUnregister(proc2)
+	fmt.Println(ProcessCount())
+	proc3 := NewProcess("dhcp", args...)
+	ProcessUnregister(proc3)
+	fmt.Println(ProcessCount())
+
+	ProcessUnregister(proc1)
+	fmt.Println(ProcessCount())
 }