GoLearn/go圣经/1.3/dup2.go

// Dup2 prints the count and text of lines that appear more than once
// in the input.  It reads from stdin or from a list of named files.
package main

import (
	"bufio"
	"fmt"
	"os"
)

func Test() {
	fmt.Printf("test message!")
}

func DUP2() {
	counts := make(map[string]int)
	files := os.Args[1:]
	for _,value := range files {
		f,err :=os.Open(value)
		fmt.Printf("内容:%s\n",value)
		fmt.Print(f,err) // 地址
	}

	if len(files) == 0 {
		countLines(os.Stdin, counts)
	} else {
		for _, arg := range files {
			f, err := os.Open(arg)
			if err != nil {
				fmt.Fprintf(os.Stderr, "dup2: %v\n", err)
				continue
			}
			countLines(f, counts)
			f.Close()
		}
	}
	for line, n := range counts {
		fmt.Printf("%d\t%s\n", n, line)
	}
}

//这里是读的文件内容
func countLines(f *os.File, counts map[string]int) {
	input := bufio.NewScanner(f)
	for input.Scan() && input.Text() != "end!" {  //读取file的输入.--todo:这里的读取过程，会报错么，该怎么改
		counts[input.Text()]++
	}
	// NOTE: ignoring potential errors from input.Err()
}