How to flush data from a bufio.Writer to the underlying writer in Go?

You can use the Flush() method provided by the bufio.Writer type in Go to flush the buffered data to the underlying writer.

Here's an example:

package main

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

func main() {
	file, err := os.Create("output.txt")
	if err != nil {
		fmt.Println(err)
		return
	}
	defer file.Close()

	writer := bufio.NewWriter(file)
	writer.WriteString("Hello, World!")
	writer.Flush() // Flushes the buffered data to the file

	fmt.Println("Data flushed successfully")
}

In this example, we create a new file called "output.txt" and create a bufio.Writer to write data to the file. After writing the data using WriteString(), we call Flush() to flush the data to the underlying writer (in this case, the file). Finally, we print a success message indicating that the data has been flushed successfully.

Note that calling Flush() is not always necessary, as the bufio.Writer implements a buffer that automatically flushes data when necessary (e.g., when the buffer is full). However, in certain cases, you may want to manually flush the data to ensure it is written immediately.