Golang中文件目录操作的实现步骤详解

package main
import (
	"fmt"
	"io"
	"os"
)
func main() {
    //只读方式打开当前目录下的main.go文件
	file, err := os.Open("D:/GoLang/go_demo/helloworld/hello.go")
	defer file.Close() //必须关闭文件流
	if err != nil {
		fmt.Println(err)
		return
	}
	//操作文件
	fmt.Println(file) //&{0xc000100780}
	//读取文件里面的内容
	var strSlice []byte
	var tempSlice = make([]byte, 20)
	for {
		n, err := file.Read(tempSlice)
		if err == io.EOF { //err == io.EOF表示读取完毕
			fmt.Println("读取完毕")
			break
		}
		if err != nil {
			fmt.Println("读取失败")
			return
		}
		strSlice = append(strSlice, tempSlice[:n]...) //注意写法
	}
	fmt.Println(string(strSlice)) //强制类型转换
}

package main
import (
	"bufio"
	"fmt"
	"io"
	"os"
)
func main() {
    file, err := os.Open("D:/GoLang/go_demo/helloworld/hello.go")
	defer file.Close() //必须关闭文件流
	if err != nil {
		fmt.Println(err)
		return
	}
	//bufio读取文件
	var fileStr string
	reader := bufio.NewReader(file)
	for {
		line, err := reader.ReadString('\n') //表示一次读取一行
		if err == io.EOF {
			fileStr += line
			break
		}
		if err != nil {
			fmt.Println(err)
			return
		}
		fileStr += line
	}
	fmt.Println(fileStr)
}

package main
import (
	"fmt"
	"io/ioutil"
)
func main() {
    byteStr, err := ioutil.ReadFile("D:/GoLang/go_demo/helloworld/hello.go")
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Println(string(byteStr))
}

func OpenFile(name string, flag int, perm FileMode) (*File, error) {
	testlog.Open(name)
	f, err := openFileNolog(name, flag, perm)
	if err != nil {
		return nil, err
	}
	f.appendMode = flag&O_APPEND != 0
	return f, nil
}

package main
import (
	"fmt"
	"os"
)
func main() {
    file, err := os.OpenFile("D:/GoLang/go_demo/helloworld/hello.go", os.O_CREATE|os.O_APPEND, 0666)
	defer file.Close()
	if err != nil {
		fmt.Println(err)
		return
	}
	file.WriteString("//直接写入的字符串数据")
}

package main
import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)
func main() {
    file, err := os.OpenFile("D:/GoLang/go_demo/helloworld/hello.go", os.O_CREATE|os.O_APPEND, 0666)
	defer file.Close()
	if err != nil {
		fmt.Println(err)
		return
	}
	writer := bufio.NewWriter(file)
	for i := 0; i < 10; i++ {
		writer.WriteString("//你好Golang" + strconv.Itoa(i) + "\n")
	}
	writer.Flush()
}

package main
import (
	"fmt"
	"io/ioutil"
)
func main() {
    str := "//hello golang"
	err := ioutil.WriteFile("D:/GoLang/go_demo/helloworld/hello.go", []byte(str), 0666)
	if err != nil {
		fmt.Println(err)
		return
	}
}

package main
import (
	"fmt"
	"io/ioutil"
)
func main() {
    byteStr, err1 := ioutil.ReadFile("D:/GoLang/go_demo/helloworld/hello.go")
	if err1 != nil {
		fmt.Println(err1)
		return
	}
	err2 := ioutil.WriteFile("D:/GoLang/go_demo/helloworld/world.go", byteStr, 0666)
	if err2 != nil {
		fmt.Println(err2)
		return
	}
	fmt.Println("复制文件成功 ")
}

package main
import (
	"fmt"
	"io"
	"os"
)
// 编写一个函数，接受两个文件路径 srcFileName 和 dstFileName
func CopyFile(srcFileName string, dstFileName string) (err error) {
	sFile, err1 := os.Open(srcFileName)
	defer sFile.Close()
	dFile, err2 := os.OpenFile(dstFileName, os.O_CREATE|os.O_WRONLY, 0666)
	defer dFile.Close()
	if err1 != nil {
		return err1
	}
	if err2 != nil {
		return err2
	}
	var tempSlice = make([]byte, 50)
	for {
		//读取数据
		n, err := sFile.Read(tempSlice)
		if err == io.EOF {
			break
		}
		if err != nil {
			return err
		}
		//写入数据
		if _, err := dFile.Write(tempSlice[:n]); err != nil {
			return err
		}
	}
	return nil
}
func main() {
    srcFile := "D:/GoLang/go_demo/helloworld/hello.go"
	dstFile := "D:/GoLang/go_demo/helloworld/world.go"
	err := CopyFile(srcFile, dstFile)
	if err == nil {
		fmt.Println("拷贝完成")
	} else {
		fmt.Printf("拷贝错误 err = %v", err)
	}
}