package daemon
 
 import (
 	"os/exec"
 	"strconv"
 	"strings"
 
 	"github.com/docker/docker/engine"
 )
 
 func (daemon *Daemon) ContainerTop(job *engine.Job) engine.Status {
 	if len(job.Args) != 1 && len(job.Args) != 2 {
 		return job.Errorf("Not enough arguments. Usage: %s CONTAINER [PS_ARGS]\n", job.Name)
 	}
 	var (
 		name   = job.Args[0]
 		psArgs = "-ef"
 	)
 
 	if len(job.Args) == 2 && job.Args[1] != "" {
 		psArgs = job.Args[1]
 	}
 

 	container, err := daemon.Get(name)
 	if err != nil {
 		return job.Error(err)
 	}
 	if !container.IsRunning() {
 		return job.Errorf("Container %s is not running", name)
 	}
 	pids, err := daemon.ExecutionDriver().GetPidsForContainer(container.ID)
 	if err != nil {
 		return job.Error(err)
 	}
 	output, err := exec.Command("ps", strings.Split(psArgs, " ")...).Output()
 	if err != nil {
 		return job.Errorf("Error running ps: %s", err)
 	}

 	lines := strings.Split(string(output), "\n")
 	header := strings.Fields(lines[0])
 	out := &engine.Env{}
 	out.SetList("Titles", header)

 	pidIndex := -1
 	for i, name := range header {
 		if name == "PID" {
 			pidIndex = i

 		}

 	}
 	if pidIndex == -1 {
 		return job.Errorf("Couldn't find PID field in ps output")
 	}

 	processes := [][]string{}
 	for _, line := range lines[1:] {
 		if len(line) == 0 {
 			continue
 		}
 		fields := strings.Fields(line)
 		p, err := strconv.Atoi(fields[pidIndex])
 		if err != nil {
 			return job.Errorf("Unexpected pid '%s': %s", fields[pidIndex], err)
 		}

 		for _, pid := range pids {
 			if pid == p {
 				// Make sure number of fields equals number of header titles
 				// merging "overhanging" fields
 				process := fields[:len(header)-1]
 				process = append(process, strings.Join(fields[len(header)-1:], " "))
 				processes = append(processes, process)

 			}
 		}
 	}

 	out.SetJson("Processes", processes)
 	out.WriteTo(job.Stdout)
 	return engine.StatusOK

 }