从输出中排除SSH命令执行状态。

huangapple
go评论185阅读模式
英文:

Exclude SSH Command Execution Status from Output

问题

我正在尝试使用Go语言开发一个SSH客户端。我编写了下面的代码来获取用户的命令，执行它们在远程服务器上，并打印响应。

下面的代码有一个小问题。在屏幕上打印输出时，会在响应的末尾打印命令执行状态（nil/错误状态）。我该如何从输出中排除这部分内容？

SSH.go

  1. package main
  3. import "fmt"
  4. import "io"
  5. import "bufio"
  6. import "os"
  7. import "net"
  8. import "golang.org/x/crypto/ssh"
  10. func main(){
  12. 	sshConfig := &ssh.ClientConfig{
  13. 		User: "[USERNAME]",
  14. 		Auth: []ssh.AuthMethod{
  15. 			ssh.Password("[PASSWORD]"),
  16. 		},
  17. 		HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
  18. 			return nil
  19. 		},
  20. 	}
  22. 	connection,err := ssh.Dial("tcp", "[IP]:[PORT]", sshConfig)
  23. 	if err != nil {
  24. 		fmt.Println("Failed to connect: %s", err)
  25. 	}
  27. 	reader := bufio.NewReader(os.Stdin)
  29. 	for{
  30. 		input, _ := reader.ReadString('\n')
  31. 		session,err := connection.NewSession()
  32. 		if err != nil {
  33. 			fmt.Println("Failed to create session: %s", err)
  34. 		}
  35. 		stdout,err := session.StdoutPipe()
  36. 		if err != nil {
  37. 			fmt.Println("Failed to get stdout: %s", err)
  38. 		}
  39. 		go io.Copy(os.Stdout, stdout)
  40. 		output := session.Run(input);
  41. 		fmt.Println(output)
  42. 	}
  44. }

当前结果

  1. hello
  2. Process exited with status 127
  3. df -hP /tmp
  4. Filesystem      Size  Used Avail Use% Mounted on
  5. /dev/sda6       198G   13G  176G   7% /
  6. <nil>

期望结果

  1. hello
  2. df -hP /tmp
  3. Filesystem      Size  Used Avail Use% Mounted on
  4. /dev/sda6       198G   13G  176G   7% /
英文:

I am trying to develop a SSH client using Go language. I've written the below code to get commands from user, execute them on the remote server and print the response.

There's a small problem with the below code. Printing output on the screen prints the command execution status(nil/error status) at the end of response. How do I exclude this from my output?

SSH.go

  1. package main
  3. import &quot;fmt&quot;
  4. import &quot;io&quot;
  5. import &quot;bufio&quot;
  6. import &quot;os&quot;
  7. import &quot;net&quot;
  8. import &quot;golang.org/x/crypto/ssh&quot;
  10. func main(){
  12. 	sshConfig := &amp;ssh.ClientConfig{
  13. 		User: &quot;[USERNAME]&quot;,
  14. 		Auth: []ssh.AuthMethod{
  15. 			ssh.Password(&quot;[PASSWORD]&quot;),
  16. 		},
  17. 		HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
  18. 			return nil
  19. 		},
  20. 	}
  22. 	connection,err := ssh.Dial(&quot;tcp&quot;, &quot;[IP]:[PORT]&quot;, sshConfig)
  23. 	if err != nil {
  24. 		fmt.Println(&quot;Failed to connect: %s&quot;, err)
  25. 	}
  27. 	reader := bufio.NewReader(os.Stdin)
  29. 	for{
  30. 		input, _ := reader.ReadString(&#39;\n&#39;)
  31. 		session,err := connection.NewSession()
  32. 		if err != nil {
  33. 			fmt.Println(&quot;Failed to create session: %s&quot;, err)
  34. 		}
  35. 		stdout,err := session.StdoutPipe()
  36. 		if err != nil {
  37. 			fmt.Println(&quot;Failed to get stdout: %s&quot;, err)
  38. 		}
  39. 		go io.Copy(os.Stdout, stdout)
  40. 		output := session.Run(input);
  41. 		fmt.Println(output)
  42. 	}
  44. }

Current Result

  1. hello
  2. Process exited with status 127
  3. df -hP /tmp
  4. Filesystem      Size  Used Avail Use% Mounted on
  5. /dev/sda6       198G   13G  176G   7% /
  6. &lt;nil&gt;

Expected Result

  1. hello
  2. df -hP /tmp
  3. Filesystem      Size  Used Avail Use% Mounted on
  4. /dev/sda6       198G   13G  176G   7% /

答案1

得分: 1

上面打印的&lt;nil&gt;是session.Run的输出，它返回一个错误（根据文档）。命令的输出已经通过以下goroutine显示在控制台上：

  1. go io.Copy(os.Stdout, stdout)

你不需要打印output，因为当session.Run调用完成时，output是nil，表示没有错误发生。更好的做法是检查错误：

  1. // ...
  2. if err := session.Run(input); err != nil {
  3.   // 处理错误
  4. }
  5. // ...
  7. [1]: https://godoc.org/golang.org/x/crypto/ssh#Session.Run
英文:

The &lt;nil&gt; pinted above is the output of session.Run, which returns an error (as per docs).

The output of the command is already being displayed on your console by the following goroutine:

  1. go io.Copy(os.Stdout, stdout)

You don't need to print the output, which is nil since no error occurs when session.Run is call complete. A better thing to do would be to check the error:

  1. // ...
  2. if err := session.Run(input); err != nil {
  3.   // handle error
  4. }
  5. // ...

huangapple
  • 本文由 发表于 2017年8月9日 13:59:09
  • 转载请务必保留本文链接：https://go.coder-hub.com/45582678.html
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