Commander (cmd) is a command/task manager that builds CLI tasks and flags out of your Go code using reflection on your data structs and functions.
To create tasks and flags to run those tasks simply define your usual struct types amd functions on them.
type Test struct {
Name string
}
func (t *Test) Hello() {
fmt.Printf("Hello %s!", t.Name)
}
Then simply call Commanderize on your struct. You can set default values by initializing your struct.
err:= Commanderize(cmd.Default, &Test{"World"})
if err!= nil {
// Do something with err
}
What Commanderize() does is, it reads all the exported fields on your struct type (only those supported by the flag pkg) and binds them to flags with their name in lower case which defaults to their initial value and uses the cmd tag as the usage string, calls internally flag.Parse() so that your fields get the parsed values if any, then parses the first argument Arg(0) which should be in the format <struct>:<method> looks for all the exported methods and executes the right one. It returns a detailed error (which you can print) if there was a problem in any of the steps. So after that you can compile your binary and run:
# binary test:hello
Hello World!
# binary -name=John test:hello
Hello John!
You can code multiple structs and pass them to Commanderize() in one call, the first parameter is an Options struct and a Default is provided (use it for now), the second one is a variadic argument which takes any number of structs so your CLI can better separate one task from another. Default usage is done via the cmd tag and you can untag fields so they aren´t checked. Any unexported member (field or function) is not checked by Commander.
type MyStruct struct {
Check bool `cmd:"Usage string for check."`
Price float64 `cmd:"Usage string for price."`
unexported string // Unexported fields do not generate flags
Untagged *SomeType `cmd:"-"` // Untagged fields do not generate flags
}
- Better documentation
- Support variadic argument functions with extra Args[1:]
- Colorize CLI