Golang exec.Command Timeout Wrapper

cmdtimeout.go

package main

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

func run(timeout int, command string, args ...string) string {

    // instantiate new command
    cmd := exec.Command(command, args...)

    // get pipe to standard output
    stdout, err := cmd.StdoutPipe()
    if err != nil {
        return "cmd.StdoutPipe() error: " + err.Error()
    }

    // start process via command
    if err := cmd.Start(); err != nil {
        return "cmd.Start() error: " + err.Error()
    }

    // setup a buffer to capture standard output
    var buf bytes.Buffer

    // create a channel to capture any errors from wait
    done := make(chan error)
    go func() {
        if _, err := buf.ReadFrom(stdout); err != nil {
            panic("buf.Read(stdout) error: " + err.Error())
        }
        done <- cmd.Wait()
    }()

    // block on select, and switch based on actions received
    select {
    case <-time.After(time.Duration(timeout) * time.Second):
        if err := cmd.Process.Kill(); err != nil {
            return "failed to kill: " + err.Error()
        }
        return "timeout reached, process killed"
    case err := <-done:
        if err != nil {
            close(done)
            return "process done, with error: " + err.Error()
        }
        return "process completed: " + buf.String()
    }
    return ""
}

func main() {
    s := run(5, "ping", "-c25", "8.8.8.8")
    fmt.Printf("output: %s\n", s)
}