golang如何通过进程名称获取进程ID？

Question

I want to get the process id by the process name in windows environment?

I find golang only has the api os.FindProcess(id) ,but no by name.

Answer 1

You can list all the processes and match them with the name you want to find, by using the updated sys call package, https://godoc.org/golang.org/x/sys , it has most of the windows api.

func Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error)
func Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error)

also see the msdn docs: https://msdn.microsoft.com/en-us/library/windows/desktop/ms684834(v=vs.85).aspx

Answer 2

I had to struggle with this too, and found the way to the solution not very straightforward, because… WinApi :)

In the end you have to create a snapshot of the current windows process list using CreateToolhelp32Snapshot . Then you get the first process in the snapshot with Process32First . After that keep iterating over the list with Process32Next , until you get the ERROR_NO_MORE_FILES error. Only then you have the whole process list.

See how2readwindowsprocesses for a working example.

Here is the gist:

const TH32CS_SNAPPROCESS = 0x00000002

type WindowsProcess struct {
    ProcessID       int
    ParentProcessID int
    Exe             string
}

func processes() ([]WindowsProcess, error) {
    handle, err := windows.CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
    if err != nil {
        return nil, err
    }
    defer windows.CloseHandle(handle)

    var entry windows.ProcessEntry32
    entry.Size = uint32(unsafe.Sizeof(entry))
    // get the first process
    err = windows.Process32First(handle, &entry)
    if err != nil {
        return nil, err
    }

    results := make([]WindowsProcess, 0, 50)
    for {
        results = append(results, newWindowsProcess(&entry))

        err = windows.Process32Next(handle, &entry)
        if err != nil {
            // windows sends ERROR_NO_MORE_FILES on last process
            if err == syscall.ERROR_NO_MORE_FILES {
                return results, nil
            }
            return nil, err
        }
    }
}

func findProcessByName(processes []WindowsProcess, name string) *WindowsProcess {
    for _, p := range processes {
        if strings.ToLower(p.Exe) == strings.ToLower(name) {
            return &p
        }
    }
    return nil
}

func newWindowsProcess(e *windows.ProcessEntry32) WindowsProcess {
    // Find when the string ends for decoding
    end := 0
    for {
        if e.ExeFile[end] == 0 {
            break
        }
        end++
    }

    return WindowsProcess{
        ProcessID:       int(e.ProcessID),
        ParentProcessID: int(e.ParentProcessID),
        Exe:             syscall.UTF16ToString(e.ExeFile[:end]),
    }
}

Answer 3

const TH32CS_SNAPPROCESS = 0x00000002

type WindowsProcess struct {
    ProcessID       int
    ParentProcessID int
    Exe             string
}

func newWindowsProcess(e *syscall.ProcessEntry32) WindowsProcess {
    // Find when the string ends for decoding
    end := 0
    for {
        if e.ExeFile[end] == 0 {
            break
        }
        end++
    }

    return WindowsProcess{
        ProcessID:       int(e.ProcessID),
        ParentProcessID: int(e.ParentProcessID),
        Exe:             syscall.UTF16ToString(e.ExeFile[:end]),
    }
}

func processes() ([]WindowsProcess, error) {
    handle, err := syscall.CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
    if err != nil {
        return nil, err
    }
    defer syscall.CloseHandle(handle)

    var entry syscall.ProcessEntry32
    entry.Size = uint32(unsafe.Sizeof(entry))
    // get the first process
    err = syscall.Process32First(handle, &entry)
    if err != nil {
        return nil, err
    }

    results := make([]WindowsProcess, 0, 50)
    for {
        results = append(results, newWindowsProcess(&entry))

        err = syscall.Process32Next(handle, &entry)
        if err != nil {
            // windows sends ERROR_NO_MORE_FILES on last process
            if err == syscall.ERROR_NO_MORE_FILES {
                return results, nil
            }
            return nil, err
        }
    }
}

func findProcessByName(processes []WindowsProcess, name string) *WindowsProcess {
    for _, p := range processes {
        if bytes.Contains([]byte(strings.ToUpper(p.Exe)),     []byte(strings.ToUpper(name))) {
            return &p
        }
    }
    return nil
}

Answer 4

This seems to do it:

package main

import (
   "fmt"
   "golang.org/x/sys/windows"
)

// unsafe.Sizeof(windows.ProcessEntry32{})
const processEntrySize = 568

func processID(name string) (uint32, error) {
   h, e := windows.CreateToolhelp32Snapshot(windows.TH32CS_SNAPPROCESS, 0)
   if e != nil { return 0, e }
   p := windows.ProcessEntry32{Size: processEntrySize}
   for {
      e := windows.Process32Next(h, &p)
      if e != nil { return 0, e }
      if windows.UTF16ToString(p.ExeFile[:]) == name {
         return p.ProcessID, nil
      }
   }
   return 0, fmt.Errorf("%q not found", name)
}

func main() {
   n, e := processID("WindowsTerminal.exe")
   if e != nil {
      panic(e)
   }
   println(n)
}

https://pkg.go.dev/golang.org/x/sys/windows#CreateToolhelp32Snapshot