broccli

go-broccli

Package bitsnops/broccli is meant to make handling command line interface easier.

You define commands with arguments, flags, attach a handler to it and package does all the parsing.

Install

Ensure you have your workspace directory created and run the following:

go get -u github.com/bitsnops/go-broccli/v2

Example

Let's start with an example covering everything. First, let's create main CLI instance and commands:

func main() {
    myCLI := broccli.NewCLI("Example", "App", "Author <a@example.com>")

    print := myCLI.AddCmd("print", "Prints out flags", func(c *CLI) int {
        fmt.Fprintf(os.Stdout, "Printing on the screen:\n%s\n%s\n\n", c.Flag("text1"), c.Arg("text2"))
        return 2
    })
    template := myCLI.AddCmd("template", "Process template", func(c *CLI) int {
        fmt.Fprintf(os.Stdout, "Do something here")
        return 0
    })
    start := myCLI.AddCmd("start", "Start the game", func(c *CLI) int {
        fmt.Fprintf(os.Stdout, "Do something here")
        return 0
    })
}

Next, let's add flags, args and required environments variables to our commands:

    print.AddFlag("text1", "a", "Text", "Text to print", TypeString, IsRequired)
    print.AddFlag("text2", "b", "Alphanum with dots", "Can have dots", TypeAlphanumeric, AllowDots)
    // If '-r' is passed, the '--text2'/'-b' flag is required
    print.AddFlag("make-text2-required", "r", "", "Make alphanumdots required", TypeBool, 0, OnTrue(func(c *Cmd) {
        c.flags["text2"].flags = c.flags["text2"].flags | IsRequired
    }))

    template.AddFlag("template", "t", "filepath", "Path to template file", TypePathFile, IsExistent|IsRequired)
    template.AddFlag("file-output", "o", "filepath", "Output to a specific file instead of stdout", TypePathFile, 0)
    template.AddFlag("number", "n", "int", "Number necessary for initialisation", TypeInt, IsRequired)

    start.AddFlag("verbose", "v", "", "Verbose mode", TypeBool, 0)
    start.AddFlag("username", "u", "username", "Username", TypeAlphanumeric, AllowDots|AllowUnderscore|IsRequired)
    start.AddFlag("threshold", "", "1.5", "Threshold, default 1.5", TypeFloat, 0)
    start.AddArg("input", "FILE", "Path to a file", TypePathFile, IRequired)
    start.AddArg("difficulty", "DIFFICULTY", "Level of difficulty (1-5), default 3", TypeInt, 0)

One of the arguments to AddFlag, AddArg or AddEnvVar is type of the value. It can be one of the Type* consts, eg. TypeInt, TypeBool, TypeString, TypePathFile etc.

Just next to the type, there is an argument that can contain additional validation flags, such as:

• IsRequired when flag/arg is required;
• AllowMultipleValues if flag/arg can have have multiple values, eg. 1,2,3, separated by comma or another character (there are flags for that such as SeparatorSemiColon etc.);
• IsExistent which will cause a flag/arg to be checked if it exists;
• IsRegularFile, IsDirectory, IsValidJSON and so on...

Check flags.go for more information on flag types.

And in the end of main() func:

    os.Exit(myCLI.Run())