How to set up goptah in golang

Golang is a modern high-performance programming language. It is characterized by fast speed, concise code, easy to learn, etc. In practical applications, Golang often requires the use of command line parameters. Among the command line parameter parsing libraries provided by Golang, goptah is a relatively powerful and easy-to-use library.

This article will introduce how to use goptah to set command line parameters. The directory of this article is as follows:

• goptah introduction
• goptah installation
• goptah configuration-FlagSet
• goptah configuration-FlagSet usage example
• goptah configuration-Parser
• goptah configuration-Parser usage example
• Summary

goptah introduction

goptah is a command line parameter in Golang A parsing library that parses command line arguments into variables in Go. goptah provides two different configuration methods: FlagSet and Parser. FlagSet is a lightweight library, Parser is a more powerful library.

goptah installation

In Golang, the installation of goptah is very simple. Just enter the following command in the terminal to install:

go get github.com/namsral/goptah

goptah configuration-FlagSet

FlagSet in goptah are some commands A collection of line identifiers, which can be used to define command line identifiers:

• String
• Int
• Bool
• Float
• Duration
• Var

Use these methods to easily define and parse command line identifiers. gopatah.FlagSet also supports subcommands, help messages, and environment variable substitution (such as replacing the --configfile flag with $MYAPP_CONF).

goptah Configuration-FlagSet Usage Example

The following is a simple example to demonstrate how to use goptah FlagSet to define and parse command line identifiers:

package main

import (
    "flag"
    "fmt"
)

func main() {
    var name string
    flag.StringVar(&name, "name", "World", "a name to say hello to")
    flag.Parse()
    fmt.Println("Hello", name)
}

In this example , we use the flag.StringVar() method to define a string type command line identifier. We then use the flag.Parse() method to parse the command line and get the value of the flag. Finally, we print "Hello" and the value of the identifier to the console.

goptah Configuration-Parser

Parser in goptah is a data structure used to parse and store command line identifiers. In goptah, command line flags can be defined using:

• FlagString
• FlagInt
• FlagBool
• FlagFloat
• FlagDuration

Unlike FlagSet, Parser also supports subcommands and help messages.

goptah Configuration-Parser Usage Example

The following is a simple example demonstrating how to use goptah Parser to define and parse command line identifiers:

package main

import (
    "fmt"
    "github.com/namsral/goptah"
)

func main() {
    var (
        name  = "World"
        count = 1
        debug = false
    )

    p := goptah.NewParser("myapp", "")

    p.FlagString(&name, "name", "n", "a name to say hello to")
    p.FlagInt(&count, "count", "c", "number of times to say hello")
    p.FlagBool(&debug, "debug", "d", "enable debug mode")

    p.Parse()

    for i := 0; i < count; i++ {
        fmt.Println("Hello", name)
    }
    if debug {
        fmt.Println("Debug mode enabled")
    }
}

In this example, We define three variables: name, count and debug. Then, we created a new goptah Parser and defined them using the FlagString(), FlagInt(), and FlagBool() methods. Then, we called the Parse() method to parse the command line identifier. Finally, we use the value of the variable to output the number of "Hello"s and the debug mode status.

Summary

In this article, we introduced how to use the goptah library to parse command line identifiers. We discussed two configuration options: FlagSet and Parser. While FlagSet is more lightweight, Parser is more powerful and supports subcommands and help messages. Whichever way you choose, goptah is a very useful library that can help you easily parse and store command line identifiers.

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