// main.go
package main
import (
	"compress/gzip"
	"fmt"
	"io"
	"log"
	"os"
)
func main() {
	// 1. 準備源文件和目標文件
	sourceFile, err := os.Open("original.txt")
	if err != nil {
		log.Fatalf("Failed to open source file: %v", err)
	}
	defer sourceFile.Close()
	destFile, err := os.Create("original.txt.gz")
	if err != nil {
		log.Fatalf("Failed to create destination file: %v", err)
	}
	// 使用 defer 確保文件在函數(shù)結(jié)束時關(guān)閉
	defer destFile.Close()
	// 2. 創(chuàng)建一個 gzip.Writer，它將壓縮數(shù)據(jù)寫入 destFile
	gzipWriter := gzip.NewWriter(destFile)
	// 使用 defer 確保在所有數(shù)據(jù)寫入后，關(guān)閉 gzip.Writer，這會寫入尾部信息
	defer gzipWriter.Close()
	// 3. 將源文件內(nèi)容拷貝到 gzip.Writer
	// io.Copy 會高效地處理數(shù)據(jù)流的拷貝
	bytesWritten, err := io.Copy(gzipWriter, sourceFile)
	if err != nil {
		log.Fatalf("Failed to compress data: %v", err)
	}
	fmt.Printf("Successfully compressed. Original size: ~%d bytes, written to gzip writer: %d bytes.\n", bytesWritten, bytesWritten)
	// 注意：gzipWriter 內(nèi)部會緩沖，實際寫入 destFile 的大小會小于 bytesWritten
}

go run main.go

// main.go
package main
import (
	"compress/gzip"
	"fmt"
	"io"
	"log"
	"os"
)
func main() {
	// 1. 打開壓縮的源文件
	gzipFile, err := os.Open("original.txt.gz")
	if err != nil {
		log.Fatalf("Failed to open gzip file: %v", err)
	}
	defer gzipFile.Close()
	// 2. 創(chuàng)建一個 gzip.Reader，它會從 gzipFile 讀取并解壓數(shù)據(jù)
	// 注意：NewReader 返回的 reader 也需要關(guān)閉，以釋放資源
	gzipReader, err := gzip.NewReader(gzipFile)
	if err != nil {
		log.Fatalf("Failed to create gzip reader: %v", err)
	}
	defer gzipReader.Close()
	// 3. 創(chuàng)建解壓后的目標文件
	destFile, err := os.Create("unzipped.txt")
	if err != nil {
		log.Fatalf("Failed to create destination file: %v", err)
	}
	defer destFile.Close()
	// 4. 將解壓后的數(shù)據(jù)從 gzipReader 拷貝到目標文件
	bytesRead, err := io.Copy(destFile, gzipReader)
	if err != nil {
		log.Fatalf("Failed to decompress data: %v", err)
	}
	fmt.Printf("Successfully decompressed. Read %d bytes from gzip stream, written to unzipped.txt.\n", bytesRead)
}

go run main.go

// main.go
package main
import (
	"bytes"
	"compress/zlib"
	"fmt"
	"io"
)
func main() {
	originalData := []byte("This is some data that we will compress using zlib in memory. " +
		"It's a very common use case for network communications.")
	fmt.Printf("Original size: %d bytes\n", len(originalData))
	fmt.Println("Original data:", string(originalData))
	// --- 壓縮 ---
	var compressedBuffer bytes.Buffer
	zlibWriter := zlib.NewWriter(&compressedBuffer)
	_, err := zlibWriter.Write(originalData)
	if err != nil {
		panic(err)
	}
	// 關(guān)閉 writer 以刷新緩沖區(qū)
	zlibWriter.Close()
	compressedData := compressedBuffer.Bytes()
	fmt.Printf("Compressed size: %d bytes\n", len(compressedData))
	// --- 解壓 ---
	// 從壓縮后的字節(jié)切片創(chuàng)建一個 reader
	zlibReader, err := zlib.NewReader(bytes.NewReader(compressedData))
	if err != nil {
		panic(err)
	}
	defer zlibReader.Close()
	var decompressedBuffer bytes.Buffer
	// 將解壓后的數(shù)據(jù)拷貝到新的緩沖區(qū)
	_, err = io.Copy(&decompressedBuffer, zlibReader)
	if err != nil {
		panic(err)
	}
	decompressedData := decompressedBuffer.Bytes()
	fmt.Printf("Decompressed size: %d bytes\n", len(decompressedData))
	fmt.Println("Decompressed data:", string(decompressedData))
	// 驗證
	if bytes.Equal(originalData, decompressedData) {
		fmt.Println("\nSuccess! Original and decompressed data match.")
	} else {
		fmt.Println("\nError! Data does not match.")
	}
}

echo "Content of file one." > file1.txt
echo "Content of file two, which is slightly longer." > file2.txt

// main.go
package main
import (
	"archive/zip"
	"io"
	"log"
	"os"
)
func main() {
	// 1. 創(chuàng)建 zip 文件
	zipFile, err := os.Create("archive.zip")
	if err != nil {
		log.Fatalf("Failed to create zip file: %v", err)
	}
	defer zipFile.Close()
	// 2. 創(chuàng)建一個 zip.Writer
	zipWriter := zip.NewWriter(zipFile)
	defer zipWriter.Close() // 關(guān)閉 writer 以寫入 zip 的中央目錄記錄
	// 3. 定義要添加的文件列表
	filesToAdd := []string{"file1.txt", "file2.txt"}
	for _, filename := range filesToAdd {
		// 3.1. 在 zip 文件中創(chuàng)建一個文件頭
		// 這相當于在 zip 內(nèi)部創(chuàng)建一個空的文件結(jié)構(gòu)
		writer, err := zipWriter.Create(filename)
		if err != nil {
			log.Fatalf("Failed to create entry for %s in zip: %v", filename, err)
		}
		// 3.2. 打開要添加的原始文件
		file, err := os.Open(filename)
		if err != nil {
			log.Fatalf("Failed to open %s: %v", filename, err)
		}
		defer file.Close()
		// 3.3. 將原始文件內(nèi)容拷貝到 zip 內(nèi)部的文件 writer 中
		_, err = io.Copy(writer, file)
		if err != nil {
			log.Fatalf("Failed to write %s to zip: %v", filename, err)
		}
		log.Printf("Added %s to archive.zip\n", filename)
	}
	log.Println("Successfully created archive.zip")
}

// main.go
package main
import (
	"archive/zip"
	"io"
	"log"
	"os"
	"path/filepath"
)
func main() {
	// 1. 打開 zip 文件
	zipReader, err := zip.OpenReader("archive.zip")
	if err != nil {
		log.Fatalf("Failed to open zip file: %v", err)
	}
	defer zipReader.Close()
	// 2. 創(chuàng)建解壓目標目錄
	destDir := "unzipped_archive"
	err = os.MkdirAll(destDir, 0755)
	if err != nil {
		log.Fatalf("Failed to create destination directory: %v", err)
	}
	// 3. 遍歷 zip 文件中的每一個文件/目錄
	for _, f := range zipReader.File {
		// 3.1. 構(gòu)造解壓后的完整文件路徑
		// filepath.Join 會處理不同操作系統(tǒng)的路徑分隔符
		destPath := filepath.Join(destDir, f.Name)
		// 安全檢查：防止 ZipSlip 漏洞（路徑遍歷攻擊）
		// 確保 f.Name 不會跳出目標目錄
		if !strings.HasPrefix(destPath, filepath.Clean(destDir)+string(os.PathSeparator)) {
			log.Fatalf("Invalid file path: %s", f.Name)
		}
		log.Printf("Extracting %s to %s", f.Name, destPath)
		// 3.2. 如果是目錄，則創(chuàng)建它
		if f.FileInfo().IsDir() {
			os.MkdirAll(destPath, f.Mode())
			continue
		}
		// 3.3. 如果是文件，則創(chuàng)建它并寫入內(nèi)容
		// 確保文件的父目錄存在
		os.MkdirAll(filepath.Dir(destPath), 0755)
		// 打開 zip 內(nèi)的文件
		rc, err := f.Open()
		if err != nil {
			log.Fatalf("Failed to open file %s in zip: %v", f.Name, err)
		}
		// 創(chuàng)建目標文件
		destFile, err := os.OpenFile(destPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
		if err != nil {
			rc.Close()
			log.Fatalf("Failed to create destination file %s: %v", destPath, err)
		}
		// 拷貝文件內(nèi)容
		_, err = io.Copy(destFile, rc)
		rc.Close()
		destFile.Close()
		if err != nil {
			log.Fatalf("Failed to write file %s: %v", destPath, err)
		}
	}
	log.Println("Successfully extracted archive.zip to unzipped_archive directory.")
}

mkdir myproject
echo "package main\n\nfunc main() {\n\tprintln(\"Hello from main.go\")\n}" > myproject/main.go
echo "module myproject\n\ngo 1.21" > myproject/go.mod

// main.go
package main
import (
	"archive/tar"
	"compress/gzip"
	"io"
	"log"
	"os"
	"path/filepath"
)
func main() {
	// 1. 創(chuàng)建最終的 .tar.gz 文件
	tarGzFile, err := os.Create("myproject.tar.gz")
	if err != nil {
		log.Fatal(err)
	}
	defer tarGzFile.Close()
	// 2. 創(chuàng)建 gzip writer，它將數(shù)據(jù)寫入 tarGzFile
	gzipWriter := gzip.NewWriter(tarGzFile)
	defer gzipWriter.Close()
	// 3. 創(chuàng)建 tar writer，它將數(shù)據(jù)寫入 gzipWriter
	tarWriter := tar.NewWriter(gzipWriter)
	defer tarWriter.Close()
	// 4. 遍歷 "myproject" 目錄，將文件添加到 tar 歸檔中
	sourceDir := "myproject"
	err = filepath.Walk(sourceDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		// 創(chuàng)建 tar 頭部信息
		header, err := tar.FileInfoHeader(info, info.Name())
		if err != nil {
			return err
		}
		// 調(diào)整頭部中的 Name，使其為相對于源目錄的路徑
		relPath, err := filepath.Rel(sourceDir, path)
		if err != nil {
			return err
		}
		header.Name = relPath
		// 寫入頭部
		if err := tarWriter.WriteHeader(header); err != nil {
			return err
		}
		// 如果是普通文件，則寫入文件內(nèi)容
		if !info.Mode().IsRegular() {
			return nil
		}
		file, err := os.Open(path)
		if err != nil {
			return err
		}
		defer file.Close()
		_, err = io.Copy(tarWriter, file)
		return err
	})
	if err != nil {
		log.Fatal(err)
	}
	log.Println("Successfully created myproject.tar.gz")
}

// main.go
package main
import (
	"archive/tar"
	"compress/gzip"
	"io"
	"log"
	"os"
	"path/filepath"
)
func main() {
	// 1. 打開 .tar.gz 文件
	tarGzFile, err := os.Open("myproject.tar.gz")
	if err != nil {
		log.Fatal(err)
	}
	defer tarGzFile.Close()
	// 2. 創(chuàng)建 gzip reader
	gzipReader, err := gzip.NewReader(tarGzFile)
	if err != nil {
		log.Fatal(err)
	}
	defer gzipReader.Close()
	// 3. 創(chuàng)建 tar reader
	tarReader := tar.NewReader(gzipReader)
	// 4. 創(chuàng)建解壓目標目錄
	destDir := "extracted_project"
	os.MkdirAll(destDir, 0755)
	// 5. 遍歷 tar 歸檔中的文件
	for {
		header, err := tarReader.Next()
		if err == io.EOF {
			break // 文件結(jié)束
		}
		if err != nil {
			log.Fatal(err)
		}
		// 構(gòu)造目標路徑
		destPath := filepath.Join(destDir, header.Name)
		// 安全檢查：防止路徑遍歷
		if !strings.HasPrefix(destPath, filepath.Clean(destDir)+string(os.PathSeparator)) {
			log.Fatalf("Invalid file path: %s", header.Name)
		}
		log.Printf("Extracting %s to %s", header.Name, destPath)
		switch header.Typeflag {
		case tar.TypeDir:
			// 如果是目錄，創(chuàng)建它
			if err := os.MkdirAll(destPath, os.FileMode(header.Mode)); err != nil {
				log.Fatal(err)
			}
		case tar.TypeReg:
			// 如果是文件，創(chuàng)建它并寫入內(nèi)容
			outFile, err := os.OpenFile(destPath, os.O_CREATE|os.O_WRONLY, os.FileMode(header.Mode))
			if err != nil {
				log.Fatal(err)
			}
			if _, err := io.Copy(outFile, tarReader); err != nil {
				outFile.Close()
				log.Fatal(err)
			}
			outFile.Close()
		}
	}
	log.Println("Successfully extracted myproject.tar.gz to extracted_project directory.")
}