Golang文件写入追加方法教程

package main

import (
    "log"
    "os"
)

func main() {
    file, err := os.OpenFile("example.txt", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
    if err != nil {
        log.Fatal(err)
    }
    defer file.Close()

    content := "这是写入的内容\n"
    _, err = file.WriteString(content)
    if err != nil {
        log.Fatal(err)
    }
}

file, err := os.OpenFile("example.txt", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
if err != nil {
    log.Fatal(err)
}
defer file.Close()

content := "这是追加的内容\n"
_, err = file.WriteString(content)
if err != nil {
    log.Fatal(err)
}

import (
    "io/ioutil"
)

err := ioutil.WriteFile("example.txt", []byte("一次性写入内容\n"), 0644)
if err != nil {
    log.Fatal(err)
}

err := os.WriteFile("example.txt", []byte("新内容\n"), 0644)
if err != nil {
    log.Fatal(err)
}

file, err := os.OpenFile("example.txt", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
if err != nil {
    log.Fatal(err)
}
defer file.Close()

writer := bufio.NewWriter(file)
lines := []string{"行1\n", "行2\n", "行3\n"}

for _, line := range lines {
    _, err := writer.WriteString(line)
    if err != nil {
        log.Fatal(err)
    }
}

// 别忘了刷新缓冲区
err = writer.Flush()
if err != nil {
    log.Fatal(err)
}