doc.go

/*
Package flag2 implements command-line flag parsing with support for config files and environment vars.

Usage:

Define flags using flag2.String(), Bool(), Int(), etc.

This declares an integer flag, -flagname, stored in the pointer ip, with type *int.
	import "flag2"
	var ip = flag2.Int("flagname", 1234, "help message for flagname")
If you like, you can bind the flag to a variable using the Var() functions.
	var flagvar int
	func init() {
		flag2.IntVar(&flagvar, "flagname", 1234, "help message for flagname")
	}
Or you can create custom flags that satisfy the Value interface (with
pointer receivers) and couple them to flag parsing by
	flag2.Var(&flagVal, "name", "help message for flagname")
For such flags, the default value is just the initial value of the variable.

After all flags are defined, call
	flag2.Parse()
to parse the command line into the defined flags.

Flags may then be used directly. If you're using the flags themselves,
they are all pointers; if you bind to variables, they're values.
	fmt.Println("ip has value ", *ip)
	fmt.Println("flagvar has value ", flagvar)

After parsing, the arguments following the flags are available as the
slice flag2.Args() or individually as flag2.Arg(i).
The arguments are indexed from 0 through flag2.NArg()-1.

Command line flag syntax:
	-flag
	-flag=x
	-flag x  // non-boolean flags only
One or two minus signs may be used; they are equivalent.
The last form is not permitted for boolean flags because the
meaning of the command
	cmd -x *
where * is a Unix shell wildcard, will change if there is a file
called 0, false, etc. You must use the -flag=false form to turn
off a boolean flag.

Flag parsing stops just before the first non-flag argument
("-" is a non-flag argument) or after the terminator "--".

Integer flags accept 1234, 0664, 0x1234 and may be negative.
Boolean flags may be:
	1, 0, t, f, T, F, true, false, TRUE, FALSE, True, False
Duration flags accept any input valid for time.ParseDuration.

The default set of command-line flags is controlled by
top-level functions.  The FlagSet type allows one to define
independent sets of flags, such as to implement subcommands
in a command-line interface. The methods of FlagSet are
analogous to the top-level functions for the command-line
flag set.
*/
package flag2