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()
}
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
}
Do you need the call to run
be asynchronous (which would require channels and goroutines)? If not you can simply use bytes.Buffer
to capture command output and return (which is what our current implementation appears to be doing):
func run(input string) string {
cmdName := "/usr/bin/nikto"
cmdArgs := []string{"-host", input}
cmd := exec.Command(cmdName, cmdArgs...)
var b bytes.Buffer
cmd.Stdout = &b
err := cmd.Run()
if err != nil {
log.Fatal(err)
}
return b.String()
}