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package flagbind

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Package flagbind parses the exported fields of a struct and binds them to flags in a flag.FlagSet or pflag.FlagSet.

Bind allows for creating flags declaratively right alongside the definition of their containing struct. For example, the following stuct could be passed to Bind to populate a flag.FlagSet or pflag.FlagSet.

flags:=struct {
StringFlagstring`flag:"flag-name;default value;Usage for string-flag"`Intint`flag:"integer;5"`// Flag names default to `auto-kebab-case`AutoKebabCaseint// If pflag is used, -s is be used as the shorthand flag name,// otherwise it is ignored for use with the standard flag package.ShortNamebool`flag:"short,s"`// Optionally extende the usage tag with subsequent `use` tags// on _ fields.URLstring`flag:"url,u;http://www.example.com/;Start usage here" _ struct{} `use:"continuelongerusagestringfor--urlbelowit",
// Nested and Embedded structs can add a flag name prefix, or not.NestedStructANestedFlatStructB`flag:";;;flatten"`StructA// Flat by defaultStructB`flag:"embedded"`// Add prefix to nested field flag names.// IgnoredExplicitlyIgnoredbool`flag:"-"`unexportedbool
}{
// Default values may also be set directly to override the tag.StringFlag: "override default",
_URL: "Include a longer usage string for --url here",
}
fs:=pflag.NewFlagSet("", pflag.ContinueOnError)
flagbind.Bind(fs, &flags)
fs.Parse([]string{"--auto-kebab-case"})

Bind works seemlessly with both the standard library flag package and the popular [github.com/spf13/pflag](https://github.com/spf13/pflag) package.

If pflag is used, for types that implement flag.Value but not pflag.Value, Bind wraps them in an adapter so that they can still be used as a pflag.Value. The return value of the additional function Type() string is the type name of the struct field.

Additional options may be set for each flag. See Bind for the full documentation details.

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Define rich flags with struct tags to make writing CLIs a breeze

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