尝试将Shell命令的实时/实时输出作为字符串数据从函数返回到主函数

Question

not sure how to explain this since I am using QT bindings in GO so I pasted a mini version of the program. I am trying to return from the run() func a live stream to the QT window.. I try this many ways... last one with channels(not succesfully) what will be the best way to pass real time output to the main() function so my QT Slot can update the window?

package main

import (
        "fmt"
        //      "github.com/therecipe/qt/core"
        "bufio"
        "github.com/therecipe/qt/widgets"
        "os"
        "os/exec"
)

func run(input string) string {

        stream := make(chan string)

        fmt.Printf("You Clicked The Push Button %s
", input)

        cmdName := "/usr/bin/nikto"
        cmdArgs := []string{"-host", input}

        cmd := exec.Command(cmdName, cmdArgs...)
        cmdReader, err := cmd.StdoutPipe()
        if err != nil {
                fmt.Fprintln(os.Stderr, "Error creating StdoutPipe for Cmd", err)
                os.Exit(1)
        }

        scanner := bufio.NewScanner(cmdReader)
        go func() {
                for scanner.Scan() {
                        fmt.Printf("%s
", scanner.Text())
                        stream <- scanner.Text()
                        //stream = fmt.Sprintf("%s
", scanner.Text())
                }
        }()

        err = cmd.Start()
        if err != nil {
                fmt.Fprintln(os.Stderr, "Error starting Cmd", err)
                os.Exit(1)
        }

        err = cmd.Wait()
        if err != nil {
                fmt.Fprintln(os.Stderr, "Error waiting for Cmd", err)
                os.Exit(1)
        }

        input = <-stream
        return string(input)
        //return go getOutput(scanner)

}

func main() {
        // Create application
        app := widgets.NewQApplication(len(os.Args), os.Args)

        // Create main window
        window := widgets.NewQMainWindow(nil, 0)
        window.SetWindowTitle("nikto front end")
        window.SetMinimumSize2(400, 400)

        // Create layout

        Layout := widgets.NewQVBoxLayout()

        TopLayout := widgets.NewQHBoxLayout()
        //topright := widgets.NewQHBoxLauout()

        RLayout := widgets.NewQVBoxLayout()
        LLayout := widgets.NewQVBoxLayout()

        Layout.AddLayout(TopLayout, 0)
        Layout.AddLayout(RLayout, 1)
        Layout.AddLayout(LLayout, 0)

        //Create main widget
        mainWidget := widgets.NewQWidget(nil, 0)
        mainWidget.SetLayout(Layout)

        // Create left widget
        LQWidget := widgets.NewQWidget(nil, 0)
        LQWidget.SetLayout(LLayout)

        // Create right widget

        RQWidget := widgets.NewQWidget(nil, 0)
        RQWidget.SetLayout(RLayout)

        // Create label
        urlLabel := widgets.NewQLabel(nil, 0)
        urlLabel.SetText("Target: ")
        TopLayout.AddWidget(urlLabel, 0, 0)

        // Create a line edit
        input := widgets.NewQLineEdit(nil)
        input.SetPlaceholderText("Enter target like http://127.0.0.1")
        TopLayout.AddWidget(input, 0, 0)

        // Create checkboxes
        checkBox1 := widgets.NewQCheckBox2("Default", nil)
        //checkBox1.SetWindowTitle("Check Box")
        LLayout.AddWidget(checkBox1, 0, 0)

        checkBox2 := widgets.NewQCheckBox2("SSL mode", nil)
        //checkBox2.SetWindowTitle("Check Box")
        LLayout.AddWidget(checkBox2, 0, 0)

        checkBox3 := widgets.NewQCheckBox2("no 404", nil)
        //checkBox3.SetWindowTitle("Check Box")
        LLayout.AddWidget(checkBox3, 0, 0)

        output := widgets.NewQTextEdit(nil)
        LLayout.AddWidget(output, 0, 0)

        // Create a button and add it to the layout
        button1 := widgets.NewQPushButton2("2. click me", nil)
        Layout.AddWidget(button1, 0, 0)

        button1.ConnectClicked(func(checked bool) {
                output.Append(run(input.Text()))
        })

        // Set main widget as the central widget of the window
        window.SetCentralWidget(mainWidget)

        // Show the window
        window.Show()

        // Execute app
        app.Exec()
}

Answer 1

Let run return the channel, then read it in main (and don't read from the channel in run):

package main

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

func main() {
    // ...

    button1.ConnectClicked(func(checked bool) {
            stream := run(input.Text())
            go func() {
                    for line := range stream {
                            output.Append(line)
                    }
            }()
    })

    // ...
}

func run(host string) <-chan string {

    var cmd *exec.Cmd
    cmdReader, err := cmd.StdoutPipe()
    if err != nil {
            // ...
    }

    scanner := bufio.NewScanner(cmdReader)
    stream := make(chan string)

    go func() {
            defer close(stream)

            for scanner.Scan() {
                    fmt.Printf("%s
", scanner.Text())
                    stream <- scanner.Text()
            }
    }()

    go func() {
            if err := cmd.Run(); err != nil {
                    // ...
            }
    }()

    return stream
}