Thank you!

It does handle subcommands, I should write an example of that.  In short, you 
use RegisterNew to create a new getopt.Set or RegisterSet to register with a 
previously created set.  You will have to call set.Parse to parse the args to 
the subcommand.  If you need to parse a particular set multiple times that has 
default values then you will want to use Dup.  Also, you probably want a named 
structure.  Something like this (beware, I have not compiled this code):

Example with no global defaults
type cmdOpts struct { … }

     v, set := options.RegisterNew(“command”, &cmdOpts{})
     opts := v.(*cmdOpts)
     set.Parse(args)

Example with global and local defaults:
type cmdOpts struct {
Name    string        `getopt:"--name=NAME      name of the widget"`
Count   int           `getopt:"--count -c=COUNT number of widgets"`
}
var cmdGlobalOpts = &cmdOpts {
     Name: “global”,
}

opts := options.Dup(&cmdGlobalOpts).(*cmdOpts)
opts.Count = 42
     v, set := options.RegisterNew(“command”, opts)
     set.Parse(args)

I will try to get an example added to the codebase in the next week or so.

BTW, my hope is that in most common cases you can just use the options 
packages.  You can also use github.com/pborman/getopt/v2 in conjunction with 
the options package if need be.

    -Paul

From: <golang-nuts@googlegroups.com> on behalf of "mhhc...@gmail.com" 
<mhhc...@gmail.com>
Date: Wednesday, April 10, 2019 at 4:00 AM
To: golang-nuts <golang-nuts@googlegroups.com>
Subject: [go-nuts] Re: Easy to use (getopt based) flags package

looks lovely, how do you manage sub commands ?

On Wednesday, April 10, 2019 at 2:24:21 AM UTC+2, Paul Borman wrote:
I have never been quite happy with the flags packages available for Go, 
including the standard flags package as well as my own getopt packages (v1 and 
v2).  They are just too cumbersome to use.  I finally have come up with a 
solution that I like.  
github.com/pborman/options<https://godoc.org/github.com/pborman/options>

The command line options are declared as a simple structure with struct tags, 
for example:

// Declare the command line flags.  The help information does not need to line 
up,
// I just think it looks prettier this way.
var opts = struct {
Help    options.Help  `getopt:"--help           display help"`
Name    string        `getopt:"--name=NAME      name of the widget"`
Count   int           `getopt:"--count -c=COUNT number of widgets"`
Verbose bool          `getopt:"-v               be verbose"`
Timeout time.Duration `getopt:"--timeout        duration of run"`
}{
Name: “gopher”,
}

func main() {
// Assign args to the positional parameters.
args := options.RegisterAndParse(&opts)

fmt.Printf(“Name is: %s\n”, opts.Name)
…
}

The command usage displayed by passing —help to the above program will look 
something like:

Usage: prog [-v] [-c COUNT] [--help] [--name NAME] [--timeout value] 
[parameters ...]
 -c, --count=COUNT  number of widgets
     --help         display help
     --name=NAME    name of the widget [gopher]
     --timeout=value
                    duration of run
 -v                 be verbose
The package is built on top of the 
github.com/pborman/getopt/v2<https://godoc.org/github.com/pborman/getopt/v2> 
package and as such they can be used together.  The options package also 
supports reading command line arguments from a file by using the options.Flags 
type.

I hope that some of you might find this helpful in writing command line 
programs.

    -Paul
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