Get windows process handle in Go

procHandle.go

import (
    "context"
    "encoding/json"
    "fmt"
    "os"
    "os/exec"
    "strings"
    "syscall"
    "time"
    "unsafe"
    "golang.org/x/sys/windows"
)

func main() {
    ProcessUtils{}.SetWinNice(13716, windows.HIGH_PRIORITY_CLASS)
}

var (
    kernel32        = syscall.MustLoadDLL("kernel32.dll")
    procOpenProcess = kernel32.MustFindProc("OpenProcess")
)

const PROCESS_ALL_ACCESS = 0x1F0FFF

type ProcessUtils struct {
}


func (ProcessUtils) GetProcessHandle(pid int) windows.Handle {
    handle, _, _ := procOpenProcess.Call(ToUintptr(PROCESS_ALL_ACCESS), ToUintptr(true), ToUintptr(pid))
    return windows.Handle(handle)
}

func (u ProcessUtils) SetWinNice(pid int, priority uint32) error {
    handle := u.GetProcessHandle(pid)
    return windows.SetPriorityClass(handle, priority)
}
func ToUintptr(val interface{}) uintptr {
    switch t := val.(type) {
    case string:
        p, _ := syscall.UTF16PtrFromString(val.(string))
        return uintptr(unsafe.Pointer(p))
    case int:
        return uintptr(val.(int))
    default:
        _ = t
        return uintptr(0)
    }
}