src/Guestbooky-backup/cmd/guestbooky-backup/guestbooky-backup.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/cotti/Guestbooky-backup/internal/compactor"
+)
+
+func main() {
+	err := compactor.Compact(os.Args[1], os.Args[2])
+	if err != nil {
+		fmt.Println("An error occurred while compacting:", err.Error())
+		os.Exit(1)
+	}
+	os.Exit(0)
+}

src/Guestbooky-backup/go.mod

@@ -0,0 +1,3 @@
+module github.com/cotti/Guestbooky-backup
+
+go 1.23.1

src/Guestbooky-backup/internal/compactor/compactor.go

@@ -0,0 +1,20 @@
+package compactor
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+)
+
+func Compact(source, destination string) error {
+	fmt.Println(
+		"Compacting", source, "to", destination,
+	)
+
+	if _, err := os.Stat(source); errors.Is(err, fs.ErrNotExist) {
+		return errors.New("source file does not exist")
+	}
+
+	return nil
+}