golang flagset check to see if arg is available but has no value

To check if an argument is available but has no value using the flagset package in Go (golang), you can follow these steps:

1. Create a new flag using the flag package:

flagName := flag.String("name", "", "The name argument")

Here, we define a flag called name with an empty default value and a description.

1. Parse the command-line arguments using the flag.Parse() function:

flag.Parse()

This function reads the command-line arguments and sets the flag values accordingly.

1. Check if the flag is set but has no value:

if *flagName == "" {
    fmt.Println("The name argument is available but has no value")
}

In this step, we use the asterisk (*) to dereference the flag pointer and compare its value to an empty string. If the flag is set but has no value, we print an appropriate message.

Here is the complete code snippet:

package main

import (
    "flag"
    "fmt"
)

func main() {
    flagName := flag.String("name", "", "The name argument")
    flag.Parse()

    if *flagName == "" {
        fmt.Println("The name argument is available but has no value")
    }
}

Remember to import the necessary packages (flag and fmt) and execute the code using the go run command.