A combination command-line flag and configuration file library for Go.

// define your flags.
var procs int
flag.IntVar(&procs, "procs", runtime.NumCPU(), "GOMAXPROCS")

// set flags from configuration before parse command-line flags.
if args, err := conflag.ArgsFrom("/path/to/config.toml"); err == nil {
	flag.CommandLine.Parse(args)
}

// parse command-line flags.
flag.Parse()

and you create /path/to/config.toml

procs = 2

and run your app without option, procs flag will be set in 2 that is defined at configration file.

A priority of flag is

command-line flag > configration file > flag default value

In the above case,

You can specify positions arguments to ArgsFrom function.

[options]
flag = "value"

[other settings]
hoge = "fuga"

// parse configration only under the options section.
conflag.ArgsFrom("/path/to/config.toml", "options")

You can use list for multiple parameters. The following toml makes -flag value1 -flag value2 arguments.

flag = [ "value1", "value2" ]

If you use go-flags package, you can specify options like the following.

parser := go-flags.NewParser(&opts, go-flags.Default)

conflag.LongHyphen = true
conflag.BoolValue = false
if args, err := conflag.ArgsFrom("/path/to/config.toml"); err == nil {
        parser.ParseArgs(args)
}

• Combine command-line flag and configuration file.
• Specify configration section.
• Specify list parameters.
• Support TOML configuration file.
• Support JSON configuration file.
• Support YAML configuration file.

$ go get github.com/monochromegane/conflag

1. Fork it
2. Create a feature branch
3. Commit your changes
4. Rebase your local changes against the master branch
5. Run test suite with the go test ./... command and confirm that it passes
6. Run gofmt -s
7. Create new Pull Request

MIT

monochromegane