Golang : Get executable name behind process ID example

Problem:

You want to check if a process is actually running and at the same time you want to find out the application/executable/binary name associated with the process ID. How to do that?

Solution:

We will use the standard os and syscall functions to determine if a process is running and alive. To get the application/executable or binaray name associated with the process ID, we will use Mitchell Hashimoto's https://github.com/mitchellh/go-ps package.

To test out the program below, pluck some process ids from ps command on Linux/Unix or on Windows use the task manager

NOTE : You will not be able to query some processes because you're not the owner.

Here you go!

---

 package main

 import (
  "errors"
  "fmt"
  ps "github.com/mitchellh/go-ps"
  "os"
  "runtime"
  "strconv"
  "syscall"
 )

 // check if the process is actually running
 // However, on Unix systems, os.FindProcess always succeeds and returns
 // a Process for the given pid...regardless of whether the process exists
 // or not.
 func getProcessRunningStatus(pid int) (*os.Process, error) {
  proc, err := os.FindProcess(pid)
  if err != nil {
 return nil, err
  }

  //double check if process is running and alive
  //by sending a signal 0
  //NOTE : syscall.Signal is not available in Windows

  err = proc.Signal(syscall.Signal(0))
  if err == nil {
 return proc, nil
  }

  if err == syscall.ESRCH {
 return nil, errors.New("process not running")
  }

  // default
  return nil, errors.New("process running but query operation not permitted")
 }

 func main() {

  if len(os.Args) != 2 {
 fmt.Printf("Usage : %s processID \n ", os.Args[0]) // return the program name back to %s
 os.Exit(1) // graceful exit
  }

  pid, err := strconv.Atoi(os.Args[1])

  if err != nil {
 fmt.Println("Bad process ID supplied")
 os.Exit(-1)
  }

  //NOTE : syscall.Signal is not available in Windows
  if runtime.GOOS != "windows" {
 _, err := getProcessRunningStatus(int(pid))

 if err != nil {
 fmt.Println("Error : ", err)
 os.Exit(-1)
 }

  }

  // at this stage the Processes related functions found in Golang's OS package
  // is no longer sufficient, we will use Mitchell Hashimoto's https://github.com/mitchellh/go-ps
  // package to find the application/executable/binary name behind the process ID.

  p, err := ps.FindProcess(pid)

  if err != nil {
 fmt.Println("Error : ", err)
 os.Exit(-1)
  }

  fmt.Println("Process ID : ", p.Pid())
  fmt.Println("Parent Process ID : ", p.PPid())
  fmt.Println("Process ID binary name : ", p.Executable())

 }

---

Sample output on Mac:

./checkprocess 387

Process ID : 387

Parent Process ID : 1

Process ID binary name : Google Drive

./checkprocess 392

Process ID : 392

Parent Process ID : 1

Process ID binary name : Dropbox

./checkprocess 398

Error : process running but query operation not permitted

Sample output on Windows:

C:\work>checkprocess 8112

Process ID : 8112

Parent Process ID : 2944

Process ID binary name : cmd.exe

C:\work>checkprocess 3972

Process ID : 3972

Parent Process ID : 824

Process ID binary name : chrome.exe

C:\work>checkprocess 8132

Process ID : 8132

Parent Process ID : 236

Process ID binary name : CCC.exe

References:

https://golang.org/pkg/os/#FindProcess

https://www.socketloop.com/tutorials/golang-get-command-line-arguments

https://github.com/mitchellh/go-ps/blob/master/process.go