From 370a78842f4023c80044285ca1d2140a9161b256 Mon Sep 17 00:00:00 2001
From: WAKAYAMA Shirou <shirou.faw@gmail.com>
Date: Thu, 24 Apr 2014 01:07:38 +0900
Subject: [PATCH] start to get windows process information

---
 process_windows.go | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)

diff --git a/process_windows.go b/process_windows.go
index f83be53..a69d1a0 100644
--- a/process_windows.go
+++ b/process_windows.go
@@ -2,13 +2,116 @@
 
 package gopsutil
 
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+var (
+	procCloseHandle              = modKernel32.NewProc("CloseHandle")
+	procCreateToolhelp32Snapshot = modKernel32.NewProc("CreateToolhelp32Snapshot")
+	procProcess32First           = modKernel32.NewProc("Process32FirstW")
+	procProcess32Next            = modKernel32.NewProc("Process32NextW")
+)
+
+const (
+	ERROR_NO_MORE_FILES = 0x12
+	MAX_PATH            = 260
+)
+
+type PROCESSENTRY32 struct {
+	DwSize              uint32
+	CntUsage            uint32
+	Th32ProcessID       uint32
+	Th32DefaultHeapID   uintptr
+	Th32ModuleID        uint32
+	CntThreads          uint32
+	Th32ParentProcessID uint32
+	PcPriClassBase      int32
+	DwFlags             uint32
+	SzExeFile           [MAX_PATH]uint16
+}
+
+/*
+type SYSTEM_PROCESS_INFORMATION struct {
+	ULONG NextEntryOffset;
+    ULONG NumberOfThreads;
+    BYTE Reserved1[48];
+    PVOID Reserved2[3];
+    HANDLE UniqueProcessId;
+    PVOID Reserved3;
+    ULONG HandleCount;
+    BYTE Reserved4[4];
+    PVOID Reserved5[11];
+    SIZE_T PeakPagefileUsage;
+    SIZE_T PrivatePageCount;
+    LARGE_INTEGER Reserved6[6];
+}
+*/
+
 func Pids() ([]int32, error) {
 	ret := make([]int32, 0)
 
+	procs, err := processes()
+	if err != nil {
+		return ret, nil
+	}
+	for _, proc := range procs {
+		ret = append(ret, proc.Pid)
+	}
+
 	return ret, nil
 }
 
 func NewProcess(pid int32) (*Process, error) {
 	p := &Process{Pid: pid}
+
+	if (pid == 0) || (pid == 4) {
+		p.Cmdline = ""
+	}
 	return p, nil
 }
+
+func copy_params(pe32 *PROCESSENTRY32, p *Process) error {
+	p.Ppid = int32(pe32.Th32ParentProcessID)
+
+	return nil
+}
+
+// Get processes
+// This is borrowed from go-ps
+func processes() ([]*Process, error) {
+	handle, _, _ := procCreateToolhelp32Snapshot.Call(
+		0x00000002,
+		0)
+	if handle < 0 {
+		return nil, syscall.GetLastError()
+	}
+	defer procCloseHandle.Call(handle)
+
+	var entry PROCESSENTRY32
+	entry.DwSize = uint32(unsafe.Sizeof(entry))
+	ret, _, _ := procProcess32First.Call(handle, uintptr(unsafe.Pointer(&entry)))
+	if ret == 0 {
+		return nil, fmt.Errorf("Error retrieving process info.")
+	}
+
+	results := make([]*Process, 0)
+	for {
+		pid := int32(entry.Th32ProcessID)
+		p, err := NewProcess(pid)
+		if err != nil {
+			break
+		}
+		copy_params(&entry, p)
+		results = append(results, p)
+
+		ret, _, _ := procProcess32Next.Call(handle, uintptr(unsafe.Pointer(&entry)))
+		if ret == 0 {
+			break
+		}
+	}
+
+	return results, nil
+}