winprocesses.go

package main

import (
	"github.com/AllenDang/w32"
	"io"
	"os"
	"unsafe"
	"errors"
	"fmt"
	"syscall"
)

func printModuleInfo(out io.Writer, me32 *w32.MODULEENTRY32) {
	fmt.Fprintf(out, "\t%s\n", syscall.UTF16ToString(me32.SzModule[:]))
	// fmt.Printf(out, "Exe: %s\n", syscall.UTF16ToString(me32.SzExePath[:]))
}

func printProcessInfo(out io.Writer, pid uint32) error {
	snap := w32.CreateToolhelp32Snapshot(w32.TH32CS_SNAPMODULE, pid)
	if snap == 0 {
		return errors.New("snapshot could not be created")
	}
	defer w32.CloseHandle(snap)
	
	var me32 w32.MODULEENTRY32
	me32.Size = uint32(unsafe.Sizeof(me32))
	if !w32.Module32First(snap, &me32) {
		return errors.New("module information retrieval failed")
	}
	
	fmt.Fprintf(out, "pid:%d\n", pid)
	printModuleInfo(out, &me32)
	for w32.Module32Next(snap, &me32) {
		printModuleInfo(out, &me32)
	}
	
	return nil
}

func main() {
	ps := make([]uint32, 255)
	var read uint32 = 0
	if !w32.EnumProcesses(ps, uint32(len(ps)), &read) {
		println("could not read processes")
		return
	}
	
	for _, p := range ps[:read / 4] {
		if p == 0 {
			continue
		}
	
		err := printProcessInfo(os.Stdout, p)
		if err != nil {
			println(err.Error())
		}
    }
}

This code will only retrieve maximum 63 running processes (255/4), you should check if ps is full and call again w32.EnumProcesses with a bigger allocated ps, see shirou/gopsutil#454

Line 43 should be

if !w32.EnumProcesses(ps, 4 * uint32(len(ps)), &read) {

because DWORD is 4 byte (but I'm sure you know this and this is just quick and dirty 😉)