package main

import "flag"

const stdin = "-"

type Config struct {
	Key     int
	Numeric bool
	Reverse bool
	Unique  bool
	Sources []string
}

func (c *Config) ParseFlags() {
	flag.IntVar(&c.Key, "k", 0, "sort via column")
	flag.BoolVar(&c.Numeric, "n", false, "compare according to string numerical value")
	flag.BoolVar(&c.Reverse, "r", false, "reverse the result of comparisons")
	flag.BoolVar(&c.Unique, "u", false, "output only the first of an equal run")

	flag.Parse()

	c.Sources = flag.Args()

	if len(c.Sources) == 0 {
		c.Sources = []string{stdin}
	}
}