go - 如何在golang中查找sshd服务状态

Question

我有以下代码

package main

import (
    "os/exec"
    "fmt"
    "os"
)

func main() {
    cmd := exec.Command("systemctl", "check", "sshd")
    out, err := cmd.CombinedOutput()
    if err != nil {
        fmt.Println("Cannot find process")
        os.Exit(1)
    }
    fmt.Printf("Status is: %s", string(out))
    fmt.Println("Starting Role")

如果服务关闭，程序将退出，虽然我想获得它的状态('down'，'inactive'等)

如果服务启动了，程序不会退出，会打印'active'输出

有什么提示吗？

Answer 1

如果 exec.Command 返回错误，您将退出，但您没有检查返回的错误类型。根据 docs :

If the command starts but does not complete successfully, the error is of type *ExitError. Other error types may be returned for other situations.

不只是退出，您应该检查错误是否对应于 systemctl 的非零退出代码或运行它的问题。这可以通过以下方式完成:

func main() {
  cmd := exec.Command("systemctl", "check", "sshd")
  out, err := cmd.CombinedOutput()
  if err != nil {
    if exitErr, ok := err.(*exec.ExitError); ok {
      fmt.Printf("systemctl finished with non-zero: %v\n", exitErr)
    } else {
      fmt.Printf("failed to run systemctl: %v", err)
      os.Exit(1)
    }
  }
  fmt.Printf("Status is: %s\n", string(out))
}