//+build !windows
 

 package daemon
 
 import (
 	"os/exec"
 	"strconv"
 	"strings"
 

 	derr "github.com/docker/docker/errors"

 	"github.com/docker/engine-api/types"

 )
 

 // ContainerTop lists the processes running inside of the given
 // container by calling ps with the given args, or with the flags
 // "-ef" if no args are given.  An error is returned if the container
 // is not found, or is not running, or if there are any problems
 // running ps, or parsing the output.

 func (daemon *Daemon) ContainerTop(name string, psArgs string) (*types.ContainerProcessList, error) {

 	if psArgs == "" {

 		psArgs = "-ef"
 	}
 

 	container, err := daemon.GetContainer(name)

 	if err != nil {

 		return nil, err

 	}

 	if !container.IsRunning() {

 		return nil, derr.ErrorCodeNotRunning.WithArgs(name)

 	}

 	pids, err := daemon.ExecutionDriver().GetPidsForContainer(container.ID)

 	if err != nil {

 		return nil, err

 	}

 	output, err := exec.Command("ps", strings.Split(psArgs, " ")...).Output()
 	if err != nil {

 		return nil, derr.ErrorCodePSError.WithArgs(err)

 	}

 	procList := &types.ContainerProcessList{}
 

 	lines := strings.Split(string(output), "\n")

 	procList.Titles = strings.Fields(lines[0])

 	pidIndex := -1

 	for i, name := range procList.Titles {

 		if name == "PID" {
 			pidIndex = i

 		}

 	}
 	if pidIndex == -1 {

 		return nil, derr.ErrorCodeNoPID

 	}

 	// loop through the output and extract the PID from each line

 	for _, line := range lines[1:] {
 		if len(line) == 0 {
 			continue
 		}
 		fields := strings.Fields(line)
 		p, err := strconv.Atoi(fields[pidIndex])
 		if err != nil {

 			return nil, derr.ErrorCodeBadPID.WithArgs(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(procList.Titles)-1]
 				process = append(process, strings.Join(fields[len(procList.Titles)-1:], " "))
 				procList.Processes = append(procList.Processes, process)

 			}
 		}
 	}

 	daemon.LogContainerEvent(container, "top")

 	return procList, nil

 }