Clean Install function and Download function

cmd/packets/main.go

@@ -1,15 +1,19 @@
 package main
 
 import (
+	"archive/tar"
 	"database/sql"
 	"errors"
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"packets/internal"
 	"path/filepath"
+	"strings"
 	"time"
 
+	"github.com/klauspost/compress/zstd"
 	"github.com/pelletier/go-toml/v2"
 	"github.com/spf13/cobra"
 	_ "modernc.org/sqlite"
@@ -97,6 +101,88 @@ func init() {
 	}
 }
 
+// Install exctract and install from a package file
+func Install(file *os.File) error {
+
+	manifest, err := internal.ReadManifest(file)
+	if err != nil {
+		return err
+	}
+
+	name := &manifest.Info.Name
+
+	configuration, err := internal.GetConfigTOML()
+	if err != nil {
+		return err
+	}
+
+	destDir := filepath.Join(configuration.Config.Data_d, *name)
+
+	zstdReader, err := zstd.NewReader(file)
+	if err != nil {
+		return err
+	}
+	defer zstdReader.Close()
+
+	tarReader := tar.NewReader(zstdReader)
+
+	for {
+		hdr, err := tarReader.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		rel := filepath.Clean(hdr.Name)
+
+		if rel == ".." || strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
+			continue
+		}
+
+		if err := os.MkdirAll(destDir, 0755); err != nil {
+			return err
+		}
+
+		absPath := filepath.Join(destDir, rel)
+
+		switch hdr.Typeflag {
+
+		case tar.TypeDir:
+			err = os.MkdirAll(absPath, os.FileMode(hdr.Mode))
+
+			if err != nil {
+				return err
+			}
+
+		case tar.TypeReg:
+			err = os.MkdirAll(filepath.Dir(absPath), 0755)
+			if err != nil {
+				return err
+			}
+
+			out, err := os.Create(absPath)
+			if err != nil {
+				return err
+			}
+
+			_, err = io.Copy(out, tarReader)
+			out.Close()
+			if err != nil {
+				return err
+			}
+
+			err = os.Chmod(absPath, os.FileMode(hdr.Mode))
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
 // COBRA CMDS
 
 var rootCmd = &cobra.Command{Use: "packets"}