How to use bufio.NewReaderSize and bufio.NewWriterSize together in Go?

You can use bufio.NewReaderSize and bufio.NewWriterSize together in Go to efficiently read and write to a buffered reader and writer with a specific buffer size.

Here is an example of how you can use them together:

package main

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

func main() {
	// Open a file for reading
	file, err := os.Open("input.txt")
	if err != nil {
		fmt.Println("Error opening file:", err)
		return
	}
	defer file.Close()

	// Create a buffered reader with a buffer size of 4096
	reader := bufio.NewReaderSize(file, 4096)

	// Create a buffered writer with a buffer size of 4096
	writer := bufio.NewWriterSize(os.Stdout, 4096)

	// Read from the buffered reader
	for {
		// Read a line from the input file
		line, err := reader.ReadString('\n')
		if err != nil {
			break
		}

		// Write the line to the buffered writer
		_, err = writer.WriteString(line)
		if err != nil {
			fmt.Println("Error writing line:", err)
			break
		}
	}

	// Flush the remaining data from the buffered writer
	err = writer.Flush()
	if err != nil {
		fmt.Println("Error flushing writer:", err)
	}
}

In this example, we open a file for reading and create a buffered reader with a buffer size of 4096 bytes using bufio.NewReaderSize. We also create a buffered writer with a buffer size of 4096 bytes using bufio.NewWriterSize, which writes to the standard output (os.Stdout).

We then read from the buffered reader using the ReadString function to read lines from the file, and write each line to the buffered writer using the WriteString function. Finally, we flush the remaining data from the buffered writer using the Flush method.

You can modify this example to suit your specific needs, such as reading from a different source or writing to a different destination.