golangHow to write file line by line

package main

import (
  "bufio"
	"os"
)

func main() {
  lines := []string{"first line", "second line" , "third line"}
	f, _ :=os.OpenFile("/tmp/go.txt", os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
  defer f.Close()
  dw := bufio.NewWriter(f)
  
  for _, l := range lines {
    dw.WriteString(l + "\n")
  }
  
  dw.Flush()
}ctrl + cgithub

`package main` default package declaration	`"os"` include operating-system level library
`func main() {` declare `main` function that will be launched automatically	`lines` sample slices with 3 text lines to write to file
`"bufio"` package to efficiently work with buffers (including writing to files)	`os.OpenFile` opens file handler
`/tmp/go.txt` path to file to write content to	`bufio.NewWriter` create new buffer from specified file handler
`.WriteString(` writes specified string to buffer	`dw.Flush()` flush buffer (to write changes to file)

Usage example

package main

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

func main() {
    lines := []string{"first line", "second line" , "third line"}
    f, _ := os.OpenFile("/tmp/go.txt", os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
  defer f.Close()
  dw := bufio.NewWriter(f)

  for _, l := range lines {
    dw.WriteString(l + "\n")
  }

  dw.Flush()

  t, _ := os.ReadFile("/tmp/go.txt")
  fmt.Println(string(t))
}

output

first line
second line
third line

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golangHow to write file line by line

Usage example

output

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