Master the command line interface and user interaction of Go language

Master the command line interface and user interaction of Go language

Introduction:
As an efficient, powerful and easy-to-use programming language, the application of Go language The scope is getting wider. In actual development, many Go programs need to interact with users and display corresponding information on the command line interface. This article will introduce how to use the Go language to implement command line interface and user interaction.

1. Processing of command line parameters
In Go language, you can use os.Args to obtain command line parameters. os.Args is a string slice, where the first element is the path of the program, and the following elements are the parameters entered by the user. We can use len(os.Args) to get the number of parameters, and use os.Args[index] to get the parameters at the specified position.

Here is a sample code to get the command line parameters and print them out:

package main

import (
    "fmt"
    "os"
)

func main() {
    for index, arg := range os.Args {
        fmt.Printf("参数%d：%s
", index, arg)
    }
}

Run the above code and enter go run main.go hello world# on the command line ##, you can see the output result as follows:

参数0：/tmp/go-build699359158/b001/exe/main
参数1：hello
参数2：world

In the Go language, you can use the
NewReader## of the bufio package #Function to create a reader object, and then read the string input by the user by calling the ReadString(delim byte) method, where the delim parameter is used to specify the end of the input separator. The following is a sample code for reading a string entered by the user and printing it:

package main

import (
    "bufio"
    "fmt"
    "os"
)

func main() {
    reader := bufio.NewReader(os.Stdin)

    fmt.Print("请输入一个字符串：")
    input, _ := reader.ReadString('
')

    fmt.Println("你输入的字符串是：", input)
}

Run the above code, the user will be prompted to enter a string on the command line, and Print the string entered by the user.

3. Beautification of the command line interface

github.com/gdamore/tcell
and github.com/mgutz/ ansi to beautify the command line interface. The following is a simple sample code implemented using the

library to draw a green box on the command line:

package main

import (
    "github.com/gdamore/tcell"
    "github.com/gdamore/tcell/views"
)

func main() {
    app := tcell.NewApplication()
    view := views.NewBoxLayout(views.Vertical)

    box := views.NewBox()
    box.SetBackgroundColor(tcell.ColorGreen)
    box.SetOrientation(views.Horizontal)
    box.SetContent(views.NewTextCell("Hello, World"))

    view.AddWidget(box, 0)
    view.SetRect(0, 0, 30, 10)

    if err := app.SetRootWidget(view).Run(); err != nil {
        panic(err)
    }
}