91_Go基础_1_59 file.Write

package main

import (
    "fmt"
    "log"
    "os"
)

func HandleErr(err error) {
    if err != nil {
        log.Fatal(err)
    }
}

func main() {
    /*
        写入数据：
    */

    fileName := "D:\\Go\\web2\\aa.txt"
    file, err := os.OpenFile(fileName, os.O_CREATE|os.O_WRONLY|os.O_APPEND, os.ModePerm)
    HandleErr(err)
    defer file.Close()

    // 写入数据
    bs := []byte{97, 98, 99, 100} //a,b,c,d
    n, err := file.Write(bs[:2])  // n,err := file.Write(bs)
    fmt.Println(n)                // 2
    HandleErr(err)
    file.WriteString("\n")

    // 直接写入字符串
    n, err = file.WriteString("HelloWorld")
    fmt.Println(n) // 10
    HandleErr(err)

    file.WriteString("\n")
    n, err = file.Write([]byte("today"))
    fmt.Println(n) // 5
    HandleErr(err)

}