I want the command-line options before and after the command-line arguments in the flag package in Go language.

We are currently implementing a simple curl command in the Go language.
Command-line options are intended only for -v, -x, -o, -d and are configured as follows:

//Configuring Options
    var showHeader pool
    flag.BoolVar(&showHeader, "v", false, "-v, -- verbose Make the operation more talkative")
    var outputFile string
    flag.StringVar(&outputFile, "o", "", "-o, --output<file>Write to file installed of stdout")
    var postValues string
    flag.StringVar(&postValues, "d", "", "-d, --data<data>HTTP POST data")
    var requestType string
    flag.StringVar(&requestType, "X", "GET", "-X, --request<command>Specify request command to use")
    flag.Parse()

After that, after configuring the HTTP client, the request is skipped by branching as follows:

addr:=flag.Arg(0)
// Branch at GET or POST
    if requestType == "GET" {
        get(client,addr,showHeader,outputFile)
    } else if requestType=="POST" {
        post(client,addr,showHeader,values)
    } else {
        fmt.Printf("%s:requestType is not correct!\n", os.Args[0])
        fmt.Printf("%s:try'kcurl --help'or'kcurl --manual' for more information\n", os.Args[0])
        os.Exit(1)
    }

However, in the program you created,
Only the format where the command line option precedes the command line argument (URL), such as gorunmain.go-v-otest.txt 'http://google.com', and the format where gorunmain.go'-otest.txt-v recognizes the -v-otest.txt as a string and leaves the default value as the -o option value.

fmt.Println(flag.Args())    
fmt.Println (showHeader, outputFile, postValues, requestType)

// [http://google.com-v-o test.txt]
// false GET

In this case, how should I set the flag?
I would appreciate it if you could let me know.

2022-09-30 21:51

1 Answers

The flag package does not assume this way.

https://golang.org/pkg/flag/

Flag parsing stops just before the first non-flag argument ("-"is an non-flag argument) or after the terminator" -- ".

As the document says, if a flag follows a non-flag argument, the flag package does not parse the argument as a flag.The flag package has chosen this kind of design.Learn more: https://github.com/golang/go/issues/4513

If you want to do this, for example, you will use a third-party package.Various things are known, so please choose according to your usage: https://awesome-go.com/ #command-line

2022-09-30 21:51

If you have any answers or tips

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