How do you work with command-line arguments in Go?

In Go, using command-line arguments can be achieved by leveraging the Args variable from the os package. os.Args is a string slice that contains all command-line arguments passed to the program when it is launched. os.Args[0] represents the program name, and os.Args[1:] contains the arguments passed to the program.

Here is a basic example of using command-line arguments:

go
package main

import (
    "fmt"
    "os"
)

func main() {
    // Check the number of command-line arguments
    if len(os.Args) < 2 {
        fmt.Println("Please provide at least one argument!")
        return
    }

    // Iterate over all arguments received from the command line
    for index, arg := range os.Args[1:] {
        fmt.Printf("Argument %d: %s\n", index+1, arg)
    }
}

Assuming our program is named example, we can run it in the command line as:

shell
$ go run example.go arg1 arg2 arg3

The program will output:

shell
Argument 1: arg1
Argument 2: arg2
Argument 3: arg3

This program first checks if sufficient command-line arguments are provided (at least one argument is required). Then, it iterates over the os.Args[1:] slice, which excludes the program name and contains only the arguments passed to the program.

This example demonstrates how to receive and process command-line arguments, which is very useful in many command-line applications. For instance, you can modify the program's behavior based on the passed arguments, handle file input/output, or configure the program's settings.