如何使用exec命令从golang向python发送字节数据？

Question

Main.go

func main() {
    bytearray=getbytearray()//getting an array of bytes
    cmd := exec.Command("python3", "abc.py")
    in:=cmd.Stdin
    cmd.Run()
}

I want to send the byte array as input for the python script

abc.py

import sys
newFile.write(sys.stdin) //write the byte array got as input to the newfile

How do i send bytes from golang to python and save that into a file?

Answer 1

You can access the process' stdin by calling Cmd.StdinPipe on your exec.Command. This gives you a WriteCloser that closes automatically when the process terminates.

The write to stdin must be done in a separate goroutine from the cmd.Run call.

Here is a simple example writing "Hi There!" (as a byte array) to stdin.

package main

import (
  "fmt"
  "os/exec"
)

func main() {
  byteArray := []byte("hi there!")
  cmd := exec.Command("python3", "abc.py")

  stdin, err := cmd.StdinPipe()
  if err != nil {
    panic(err)
  } 

  go func() {
    defer stdin.Close()
    if _, err := stdin.Write(byteArray); err != nil {
      panic(err) 
    }
  }()

  fmt.Println("Exec status: ", cmd.Run())
}

You'll also want to actually read from stdin in python:

import sys
f = open('output', 'w')
f.write(sys.stdin.read())