package main

import (
    "archive/zip"
    "fmt"
    "io"
    "os"
    "path/filepath"
)

// Zips "./input" into "./output.zip"
func main() {
    zipFile, err := os.Create("output.zip")
    if err != nil {
        panic(err) // サンプルコードなのでpanicしています
    }
    defer zipFile.Close()

    w := zip.NewWriter(zipFile)
    defer w.Close()

    walker := func(path string, info os.FileInfo, err error) error {
        if err != nil {
            return err
        }
        if info.IsDir() {
            return nil // ディレクトリは無視してOK（ファイル追加のときに自動で追加されるため）
        }
        file, err := os.Open(path)
        if err != nil {
            return err
        }
        defer file.Close()

        // Ensure that `path` is not absolute; it should not start with "/".
        // This snippet happens to work because I don't use 
        // absolute paths, but ensure your real-world code 
        // transforms path into a zip-root relative path.
        f, err := w.Create(path)
        if err != nil {
            return err
        }

        _, err = io.Copy(f, file)
        return err
    }
    
    if err = filepath.Walk("input", walker); err != nil {
        panic(err) // サンプルコードなのでpanicしています
    }
}

package main

import (
	"archive/zip"
	"fmt"
	"os"
)

func main() {
	zipFile, err := os.Create("output.zip")
	if err != nil {
        panic(err) // サンプルコードなのでpanicしています
	}
	defer zipFile.Close()

	w := zip.NewWriter(zipFile)
	defer w.Close()
	
	if err := w.AddFS(os.DirFS("input")); err != nil {
		panic(err)
	}
}

package main

import (
	"archive/zip"
	"fmt"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/endpoints"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
	"github.com/jszwec/s3fs"
	"os"
)

func main() {

	zipFile, err := os.Create("output.zip")
	if err != nil {
		return
	}
	defer zipFile.Close()

	w := zip.NewWriter(zipFile)
	defer w.Close()

	fs := s3fs.New(s3.New(session.Must(session.NewSessionWithOptions(session.Options{
		Profile:           "YOUR PROFILE",
		SharedConfigState: session.SharedConfigEnable,
		Config: aws.Config{
			Region: aws.String(endpoints.ApNortheast1RegionID),
		},
	}))), "my-example-bucket")

	if err := w.AddFS(fs); err != nil {
		panic(err)
	}
	fmt.Println("finish")
}

func (s *Scanner) Split(split SplitFunc)

type SplitFunc func(data []byte, atEOF bool) (advance int, token []byte, err error)

func main() {
	const input = "1,2,STOP,4,"

 	// Scannerの宣言
	scanner := bufio.NewScanner(strings.NewReader(input))

 	// SplitFunc
	onComma := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		for i := 0; i < len(data); i++ {
			if data[i] == ',' {
				// if the token is "STOP", ignore the rest
				if string(data[:i]) == "STOP" {
					return i + 1, nil, bufio.ErrFinalToken
				}

				return i + 1, data[:i], nil
			}
		}
		return 0, data, bufio.ErrFinalToken
	}
 	// ScannerにSplitFuncを設定
	scanner.Split(onComma)

	// 読み取り処理（SplitFuncで入力を分割しながら読み取れる）
	for scanner.Scan() {
		fmt.Printf("Got a token %q\n", scanner.Text())
	}
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "reading input:", err)
	}
}

func (s *SectionReader) Outer() (r ReaderAt, off int64, n int64)

package main

import (
	"io"
	"log"
	"os"
	"strings"
)

func main() {
	r := strings.NewReader("some io.Reader stream to be read\n")
	s := io.NewSectionReader(r, 5, 17)

	if _, err := io.Copy(os.Stdout, s); err != nil { // 「io.Reader stream」と出力
 		log.Fatal(err)
	}

}