package main

import (
	"bufio"
	"compress/gzip"
	"flag"
	"fmt"
	"io"
	"log"
	"os"
	"strings"
)

func openGzipFile() {
	fName := "/home/hu/go/src/hello.txt.gz"
	var r *bufio.Reader
	fi, err := os.Open(fName)
	defer fi.Close()
	if err != nil {
		fmt.Fprintf(os.Stderr, "%v,Can't open %s:error:%s\n", os.Args[0], fName, err)
		os.Exit(1)
	}
	fz, err := gzip.NewReader(fi)
	if err != nil {
		fmt.Fprintf(os.Stderr, "open gzip failed,err:%v\n", err)
		return
	}
	r = bufio.NewReader(fz)
	for {
		line, err := r.ReadString('\n')
		if err != nil {
			fmt.Println("Done reading file")
			os.Exit(0)
		}
		fmt.Println(line)
	}
}
func WriteFile() {
	fName := "/home/hu/go/src/world.txt"
	outputFile, outputError := os.OpenFile(fName, os.O_WRONLY|os.O_CREATE, 0755)
	if outputError != nil {
		fmt.Printf("An error occurred with file creation\n")
		return
	}
	defer outputFile.Close()
	outputWriter := bufio.NewWriter(outputFile)
	outputString := "hello world\n"
	for i := 0; i < 10; i++ {
		outputWriter.WriteString(outputString)
	}
	outputWriter.Flush()
}
func copyFile(dstName, srcName string) (written int64, err error) {
	src, err := os.Open(srcName)
	if err != nil {
		fmt.Println("Not found the src file or the file is damaged")
		return
	}
	defer src.Close()

	dst, err := os.OpenFile(dstName, os.O_WRONLY|os.O_CREATE, 0644)
	if err != nil {
		fmt.Println("filed to create the dst file")
		return
	}
	defer dst.Close()
	return io.Copy(dst, src)
}
func copyToTerminal() {
	r := strings.NewReader("some io.Reader stream to be read.\n")
	if _, err := io.Copy(os.Stdout, r); err != nil {
		log.Fatal(err)
	}

}
func os_Args() {
	fmt.Println("the lens of Args", len(os.Args))
	for i, v := range os.Args {
		fmt.Printf("Args[%d] is %s\n", i, v)
	}
}
func useFlag() {
	var confPath string
	var logLevel int

	flag.StringVar(&confPath, "c", "", "Please input confPath")
	flag.IntVar(&logLevel, "d", 10, "Please input logLevel")

	flag.Parse()
	fmt.Println("path:", confPath)
	fmt.Println("log level:", logLevel)
}
func main() {
	// openGzipFile()

	// WriteFile()

	// _,err:=copyFile("/home/hu/go/src/target.txt","/home/hu/go/src/hello.txt")
	// if err!=nil{
	// 	return
	// }
	// fmt.Println("Copy done!")

	// copyToTerminal()

	// os_Args()

	useFlag()

}