Different ways to read/write input in Golang

main.go

// Different ways to read/write input in Golang:
// ----------HackerRank----------
// read from 3 nums from command line
package main

import "fmt"

func main() {
	var n int
	var a int
	var b int
	fmt.Scan(&n)

	for i := 0; i < n; i++ {
		var sum int
		fmt.Scan(&a, &b)
		sum = a + b
		fmt.Println(sum)
	}
}

//-----------HackerRank-------------
import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strings"
)

// Complete the makeAnagram function below.
func makeAnagram(a string, b string) int32 {
    freqa := make(map[string]int)
		freqb := make(map[string]int)

    return 0
}

func main() {
	reader := bufio.NewReaderSize(os.Stdin, 1024*1024)
	stdout, err := os.Create(os.Getenv("OUTPUT_PATH"))
	if err != nil {
		panic(err)
	}

	defer stdout.Close()

	writer := bufio.NewWriterSize(stdout, 1024*1024)

	a := readLine(reader)
	b := readLine(reader)
	res := makeAnagram(a, b)
	fmt.Fprintf(writer, "%s\n", res)

	writer.Flush()
}

func readLine(reader *bufio.Reader) string {
	str, _, err := reader.ReadLine()
	if err == io.EOF {
		return ""
	}

	return strings.TrimRight(string(str), "\r\n")
}

//-----------Prompt user from command line--------------
import (
	"fmt"
	"os"
)

func main() {
	name := readInput("Enter your name")
	fmt.Printf("Hi %v", name)
}

func readInput(p string) (d string) {
	buf := make([]byte, 100)
	fmt.Printf("%v: ", p)

	n, err := os.Stdin.Read(buf)
	if err != nil {
		return ""
	}

	return string(buf[:n-1])
}

//-------------------------
// Read and write file line by line
package main

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

func main() {
	infile, err := os.Open("/Users/rgan/go-interpreter-compiler/input.txt")
	outfile, err := os.Create("/Users/rgan/go-interpreter-compiler/output.txt")

	if err != nil {
		log.Fatal(err)
	}
	defer infile.Close()
	defer outfile.Close()

	scanner := bufio.NewScanner(infile)
	for scanner.Scan() {
		fmt.Println(scanner.Text())

		fmt.Fprintln(outfile, scanner.Text())
		if err != nil {
			fmt.Println(err)
			return
		}

		// numBytes, err := outfile.Writeln(scanner.Text())
		if err != nil {
			fmt.Println(err)
			outfile.Close()
			return
		}

		// fmt.Println("Wrote", numBytes, "bytes")
	}

	if err := scanner.Err(); err != nil {
		log.Fatal(err)
	}
}