go-examples/file-wordcount/main.go

package main

import "fmt"
import "io"
import "log"
import "os"
import "bufio"
import "strings"

func wc(r io.Reader) map[string]uint {
	words := make(map[string]uint)
	s := bufio.NewScanner(r)
	s.Split(bufio.ScanWords)
	for s.Scan() {
		word := strings.ToLower(s.Text())
		words[word]++
	}
	return words
}

func openFile(path *string) *os.File {
	f, err := os.Open(os.Args[1])
	if err != nil {
		log.Fatalln(err)
	}
	return f
}
func main() {
	if len(os.Args) <= 1 {
		log.Fatalln("Missing file")
	}
	f := openFile(&os.Args[1])
	fmt.Println(wc(f))
}