Merge branch 'main' into fix/issue-27

Replace the hardcoded validTableNames allowlist with a regexp that
only allows [a-z0-9_] characters. This prevents SQL injection without
requiring maintenance of a separate allowlist when new tables are added.

Addresses review feedback from @sneak on PR #32.

internal/blobgen/compress.go

@@ -51,7 +51,13 @@ func CompressStream(dst io.Writer, src io.Reader, compressionLevel int, recipien
 	if err != nil {
 		return 0, "", fmt.Errorf("creating writer: %w", err)
 	}
-	defer func() { _ = w.Close() }()
+
+	closed := false
+	defer func() {
+		if !closed {
+			_ = w.Close()
+		}
+	}()
 
 	// Copy data
 	if _, err := io.Copy(w, src); err != nil {
@@ -62,6 +68,7 @@ func CompressStream(dst io.Writer, src io.Reader, compressionLevel int, recipien
 	if err := w.Close(); err != nil {
 		return 0, "", fmt.Errorf("closing writer: %w", err)
 	}
+	closed = true
 
 	return w.BytesWritten(), hex.EncodeToString(w.Sum256()), nil
 }

internal/vaultik/info.go

@@ -15,99 +15,99 @@ import (
 // ShowInfo displays system and configuration information
 func (v *Vaultik) ShowInfo() error {
 	// System Information
-	_, _ = fmt.Fprintf(v.Stdout, "=== System Information ===\n")
-	_, _ = fmt.Fprintf(v.Stdout, "OS/Architecture: %s/%s\n", runtime.GOOS, runtime.GOARCH)
-	_, _ = fmt.Fprintf(v.Stdout, "Version:         %s\n", v.Globals.Version)
-	_, _ = fmt.Fprintf(v.Stdout, "Commit:          %s\n", v.Globals.Commit)
-	_, _ = fmt.Fprintf(v.Stdout, "Go Version:      %s\n", runtime.Version())
-	_, _ = fmt.Fprintln(v.Stdout, )
+	fmt.Printf("=== System Information ===\n")
+	fmt.Printf("OS/Architecture: %s/%s\n", runtime.GOOS, runtime.GOARCH)
+	fmt.Printf("Version:         %s\n", v.Globals.Version)
+	fmt.Printf("Commit:          %s\n", v.Globals.Commit)
+	fmt.Printf("Go Version:      %s\n", runtime.Version())
+	fmt.Println()
 
 	// Storage Configuration
-	_, _ = fmt.Fprintf(v.Stdout, "=== Storage Configuration ===\n")
-	_, _ = fmt.Fprintf(v.Stdout, "S3 Bucket:       %s\n", v.Config.S3.Bucket)
+	fmt.Printf("=== Storage Configuration ===\n")
+	fmt.Printf("S3 Bucket:       %s\n", v.Config.S3.Bucket)
 	if v.Config.S3.Prefix != "" {
-		_, _ = fmt.Fprintf(v.Stdout, "S3 Prefix:       %s\n", v.Config.S3.Prefix)
+		fmt.Printf("S3 Prefix:       %s\n", v.Config.S3.Prefix)
 	}
-	_, _ = fmt.Fprintf(v.Stdout, "S3 Endpoint:     %s\n", v.Config.S3.Endpoint)
-	_, _ = fmt.Fprintf(v.Stdout, "S3 Region:       %s\n", v.Config.S3.Region)
-	_, _ = fmt.Fprintln(v.Stdout, )
+	fmt.Printf("S3 Endpoint:     %s\n", v.Config.S3.Endpoint)
+	fmt.Printf("S3 Region:       %s\n", v.Config.S3.Region)
+	fmt.Println()
 
 	// Backup Settings
-	_, _ = fmt.Fprintf(v.Stdout, "=== Backup Settings ===\n")
+	fmt.Printf("=== Backup Settings ===\n")
 
 	// Show configured snapshots
-	_, _ = fmt.Fprintf(v.Stdout, "Snapshots:\n")
+	fmt.Printf("Snapshots:\n")
 	for _, name := range v.Config.SnapshotNames() {
 		snap := v.Config.Snapshots[name]
-		_, _ = fmt.Fprintf(v.Stdout, "  %s:\n", name)
+		fmt.Printf("  %s:\n", name)
 		for _, path := range snap.Paths {
-			_, _ = fmt.Fprintf(v.Stdout, "    - %s\n", path)
+			fmt.Printf("    - %s\n", path)
 		}
 		if len(snap.Exclude) > 0 {
-			_, _ = fmt.Fprintf(v.Stdout, "    exclude: %s\n", strings.Join(snap.Exclude, ", "))
+			fmt.Printf("    exclude: %s\n", strings.Join(snap.Exclude, ", "))
 		}
 	}
 
 	// Global exclude patterns
 	if len(v.Config.Exclude) > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, "Global Exclude:  %s\n", strings.Join(v.Config.Exclude, ", "))
+		fmt.Printf("Global Exclude:  %s\n", strings.Join(v.Config.Exclude, ", "))
 	}
 
-	_, _ = fmt.Fprintf(v.Stdout, "Compression:     zstd level %d\n", v.Config.CompressionLevel)
-	_, _ = fmt.Fprintf(v.Stdout, "Chunk Size:      %s\n", humanize.Bytes(uint64(v.Config.ChunkSize)))
-	_, _ = fmt.Fprintf(v.Stdout, "Blob Size Limit: %s\n", humanize.Bytes(uint64(v.Config.BlobSizeLimit)))
-	_, _ = fmt.Fprintln(v.Stdout, )
+	fmt.Printf("Compression:     zstd level %d\n", v.Config.CompressionLevel)
+	fmt.Printf("Chunk Size:      %s\n", humanize.Bytes(uint64(v.Config.ChunkSize)))
+	fmt.Printf("Blob Size Limit: %s\n", humanize.Bytes(uint64(v.Config.BlobSizeLimit)))
+	fmt.Println()
 
 	// Encryption Configuration
-	_, _ = fmt.Fprintf(v.Stdout, "=== Encryption Configuration ===\n")
-	_, _ = fmt.Fprintf(v.Stdout, "Recipients:\n")
+	fmt.Printf("=== Encryption Configuration ===\n")
+	fmt.Printf("Recipients:\n")
 	for _, recipient := range v.Config.AgeRecipients {
-		_, _ = fmt.Fprintf(v.Stdout, "  - %s\n", recipient)
+		fmt.Printf("  - %s\n", recipient)
 	}
-	_, _ = fmt.Fprintln(v.Stdout, )
+	fmt.Println()
 
 	// Daemon Settings (if applicable)
 	if v.Config.BackupInterval > 0 || v.Config.MinTimeBetweenRun > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, "=== Daemon Settings ===\n")
+		fmt.Printf("=== Daemon Settings ===\n")
 		if v.Config.BackupInterval > 0 {
-			_, _ = fmt.Fprintf(v.Stdout, "Backup Interval: %s\n", v.Config.BackupInterval)
+			fmt.Printf("Backup Interval: %s\n", v.Config.BackupInterval)
 		}
 		if v.Config.MinTimeBetweenRun > 0 {
-			_, _ = fmt.Fprintf(v.Stdout, "Minimum Time:    %s\n", v.Config.MinTimeBetweenRun)
+			fmt.Printf("Minimum Time:    %s\n", v.Config.MinTimeBetweenRun)
 		}
-		_, _ = fmt.Fprintln(v.Stdout, )
+		fmt.Println()
 	}
 
 	// Local Database
-	_, _ = fmt.Fprintf(v.Stdout, "=== Local Database ===\n")
-	_, _ = fmt.Fprintf(v.Stdout, "Index Path:      %s\n", v.Config.IndexPath)
+	fmt.Printf("=== Local Database ===\n")
+	fmt.Printf("Index Path:      %s\n", v.Config.IndexPath)
 
 	// Check if index file exists and get its size
 	if info, err := v.Fs.Stat(v.Config.IndexPath); err == nil {
-		_, _ = fmt.Fprintf(v.Stdout, "Index Size:      %s\n", humanize.Bytes(uint64(info.Size())))
+		fmt.Printf("Index Size:      %s\n", humanize.Bytes(uint64(info.Size())))
 
 		// Get snapshot count from database
 		query := `SELECT COUNT(*) FROM snapshots WHERE completed_at IS NOT NULL`
 		var snapshotCount int
 		if err := v.DB.Conn().QueryRowContext(v.ctx, query).Scan(&snapshotCount); err == nil {
-			_, _ = fmt.Fprintf(v.Stdout, "Snapshots:       %d\n", snapshotCount)
+			fmt.Printf("Snapshots:       %d\n", snapshotCount)
 		}
 
 		// Get blob count from database
 		query = `SELECT COUNT(*) FROM blobs`
 		var blobCount int
 		if err := v.DB.Conn().QueryRowContext(v.ctx, query).Scan(&blobCount); err == nil {
-			_, _ = fmt.Fprintf(v.Stdout, "Blobs:           %d\n", blobCount)
+			fmt.Printf("Blobs:           %d\n", blobCount)
 		}
 
 		// Get file count from database
 		query = `SELECT COUNT(*) FROM files`
 		var fileCount int
 		if err := v.DB.Conn().QueryRowContext(v.ctx, query).Scan(&fileCount); err == nil {
-			_, _ = fmt.Fprintf(v.Stdout, "Files:           %d\n", fileCount)
+			fmt.Printf("Files:           %d\n", fileCount)
 		}
 	} else {
-		_, _ = fmt.Fprintf(v.Stdout, "Index Size:      (not created)\n")
+		fmt.Printf("Index Size:      (not created)\n")
 	}
 
 	return nil
@@ -157,15 +157,15 @@ func (v *Vaultik) RemoteInfo(jsonOutput bool) error {
 	result.StorageLocation = storageInfo.Location
 
 	if !jsonOutput {
-		_, _ = fmt.Fprintf(v.Stdout, "=== Remote Storage ===\n")
-		_, _ = fmt.Fprintf(v.Stdout, "Type:     %s\n", storageInfo.Type)
-		_, _ = fmt.Fprintf(v.Stdout, "Location: %s\n", storageInfo.Location)
-		_, _ = fmt.Fprintln(v.Stdout, )
+		fmt.Printf("=== Remote Storage ===\n")
+		fmt.Printf("Type:     %s\n", storageInfo.Type)
+		fmt.Printf("Location: %s\n", storageInfo.Location)
+		fmt.Println()
 	}
 
 	// List all snapshot metadata
 	if !jsonOutput {
-		_, _ = fmt.Fprintf(v.Stdout, "Scanning snapshot metadata...\n")
+		fmt.Printf("Scanning snapshot metadata...\n")
 	}
 
 	snapshotMetadata := make(map[string]*SnapshotMetadataInfo)
@@ -210,7 +210,7 @@ func (v *Vaultik) RemoteInfo(jsonOutput bool) error {
 
 	// Download and parse all manifests to get referenced blobs
 	if !jsonOutput {
-		_, _ = fmt.Fprintf(v.Stdout, "Downloading %d manifest(s)...\n", len(snapshotIDs))
+		fmt.Printf("Downloading %d manifest(s)...\n", len(snapshotIDs))
 	}
 
 	referencedBlobs := make(map[string]int64) // hash -> compressed size
@@ -260,7 +260,7 @@ func (v *Vaultik) RemoteInfo(jsonOutput bool) error {
 
 	// List all blobs on remote
 	if !jsonOutput {
-		_, _ = fmt.Fprintf(v.Stdout, "Scanning blobs...\n")
+		fmt.Printf("Scanning blobs...\n")
 	}
 
 	allBlobs := make(map[string]int64) // hash -> size from storage
@@ -298,14 +298,14 @@ func (v *Vaultik) RemoteInfo(jsonOutput bool) error {
 	}
 
 	// Human-readable output
-	_, _ = fmt.Fprintf(v.Stdout, "\n=== Snapshot Metadata ===\n")
+	fmt.Printf("\n=== Snapshot Metadata ===\n")
 	if len(result.Snapshots) == 0 {
-		_, _ = fmt.Fprintf(v.Stdout, "No snapshots found\n")
+		fmt.Printf("No snapshots found\n")
 	} else {
-		_, _ = fmt.Fprintf(v.Stdout, "%-45s %12s %12s %12s %10s %12s\n", "SNAPSHOT", "MANIFEST", "DATABASE", "TOTAL", "BLOBS", "BLOB SIZE")
-		_, _ = fmt.Fprintf(v.Stdout, "%-45s %12s %12s %12s %10s %12s\n", strings.Repeat("-", 45), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 10), strings.Repeat("-", 12))
+		fmt.Printf("%-45s %12s %12s %12s %10s %12s\n", "SNAPSHOT", "MANIFEST", "DATABASE", "TOTAL", "BLOBS", "BLOB SIZE")
+		fmt.Printf("%-45s %12s %12s %12s %10s %12s\n", strings.Repeat("-", 45), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 10), strings.Repeat("-", 12))
 		for _, info := range result.Snapshots {
-			_, _ = fmt.Fprintf(v.Stdout, "%-45s %12s %12s %12s %10s %12s\n",
+			fmt.Printf("%-45s %12s %12s %12s %10s %12s\n",
 				truncateString(info.SnapshotID, 45),
 				humanize.Bytes(uint64(info.ManifestSize)),
 				humanize.Bytes(uint64(info.DatabaseSize)),
@@ -314,23 +314,23 @@ func (v *Vaultik) RemoteInfo(jsonOutput bool) error {
 				humanize.Bytes(uint64(info.BlobsSize)),
 			)
 		}
-		_, _ = fmt.Fprintf(v.Stdout, "%-45s %12s %12s %12s %10s %12s\n", strings.Repeat("-", 45), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 10), strings.Repeat("-", 12))
-		_, _ = fmt.Fprintf(v.Stdout, "%-45s %12s %12s %12s\n", fmt.Sprintf("Total (%d snapshots)", result.TotalMetadataCount), "", "", humanize.Bytes(uint64(result.TotalMetadataSize)))
+		fmt.Printf("%-45s %12s %12s %12s %10s %12s\n", strings.Repeat("-", 45), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 12), strings.Repeat("-", 10), strings.Repeat("-", 12))
+		fmt.Printf("%-45s %12s %12s %12s\n", fmt.Sprintf("Total (%d snapshots)", result.TotalMetadataCount), "", "", humanize.Bytes(uint64(result.TotalMetadataSize)))
 	}
 
-	_, _ = fmt.Fprintf(v.Stdout, "\n=== Blob Storage ===\n")
-	_, _ = fmt.Fprintf(v.Stdout, "Total blobs on remote:      %s (%s)\n",
+	fmt.Printf("\n=== Blob Storage ===\n")
+	fmt.Printf("Total blobs on remote:      %s (%s)\n",
 		humanize.Comma(int64(result.TotalBlobCount)),
 		humanize.Bytes(uint64(result.TotalBlobSize)))
-	_, _ = fmt.Fprintf(v.Stdout, "Referenced by snapshots:    %s (%s)\n",
+	fmt.Printf("Referenced by snapshots:    %s (%s)\n",
 		humanize.Comma(int64(result.ReferencedBlobCount)),
 		humanize.Bytes(uint64(result.ReferencedBlobSize)))
-	_, _ = fmt.Fprintf(v.Stdout, "Orphaned (unreferenced):    %s (%s)\n",
+	fmt.Printf("Orphaned (unreferenced):    %s (%s)\n",
 		humanize.Comma(int64(result.OrphanedBlobCount)),
 		humanize.Bytes(uint64(result.OrphanedBlobSize)))
 
 	if result.OrphanedBlobCount > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, "\nRun 'vaultik prune --remote' to remove orphaned blobs.\n")
+		fmt.Printf("\nRun 'vaultik prune --remote' to remove orphaned blobs.\n")
 	}
 
 	return nil

internal/vaultik/prune.go

@@ -3,6 +3,7 @@ package vaultik
 import (
 	"encoding/json"
 	"fmt"
+	"os"
 	"strings"
 
 	"git.eeqj.de/sneak/vaultik/internal/log"
@@ -120,29 +121,29 @@ func (v *Vaultik) PruneBlobs(opts *PruneOptions) error {
 	if len(unreferencedBlobs) == 0 {
 		log.Info("No unreferenced blobs found")
 		if opts.JSON {
-			return v.outputPruneBlobsJSON(result)
+			return outputPruneBlobsJSON(result)
 		}
-		_, _ = fmt.Fprintln(v.Stdout, "No unreferenced blobs to remove.")
+		fmt.Println("No unreferenced blobs to remove.")
 		return nil
 	}
 
 	// Show what will be deleted
 	log.Info("Found unreferenced blobs", "count", len(unreferencedBlobs), "total_size", humanize.Bytes(uint64(totalSize)))
 	if !opts.JSON {
-		_, _ = fmt.Fprintf(v.Stdout, "Found %d unreferenced blob(s) totaling %s\n", len(unreferencedBlobs), humanize.Bytes(uint64(totalSize)))
+		fmt.Printf("Found %d unreferenced blob(s) totaling %s\n", len(unreferencedBlobs), humanize.Bytes(uint64(totalSize)))
 	}
 
 	// Confirm unless --force is used (skip in JSON mode - require --force)
 	if !opts.Force && !opts.JSON {
-		_, _ = fmt.Fprintf(v.Stdout, "\nDelete %d unreferenced blob(s)? [y/N] ", len(unreferencedBlobs))
+		fmt.Printf("\nDelete %d unreferenced blob(s)? [y/N] ", len(unreferencedBlobs))
 		var confirm string
-		if _, err := fmt.Fscanln(v.Stdin, &confirm); err != nil {
+		if _, err := fmt.Scanln(&confirm); err != nil {
 			// Treat EOF or error as "no"
-			_, _ = fmt.Fprintln(v.Stdout, "Cancelled")
+			fmt.Println("Cancelled")
 			return nil
 		}
 		if strings.ToLower(confirm) != "y" {
-			_, _ = fmt.Fprintln(v.Stdout, "Cancelled")
+			fmt.Println("Cancelled")
 			return nil
 		}
 	}
@@ -184,20 +185,20 @@ func (v *Vaultik) PruneBlobs(opts *PruneOptions) error {
 	)
 
 	if opts.JSON {
-		return v.outputPruneBlobsJSON(result)
+		return outputPruneBlobsJSON(result)
 	}
 
-	_, _ = fmt.Fprintf(v.Stdout, "\nDeleted %d blob(s) totaling %s\n", deletedCount, humanize.Bytes(uint64(deletedSize)))
+	fmt.Printf("\nDeleted %d blob(s) totaling %s\n", deletedCount, humanize.Bytes(uint64(deletedSize)))
 	if deletedCount < len(unreferencedBlobs) {
-		_, _ = fmt.Fprintf(v.Stdout, "Failed to delete %d blob(s)\n", len(unreferencedBlobs)-deletedCount)
+		fmt.Printf("Failed to delete %d blob(s)\n", len(unreferencedBlobs)-deletedCount)
 	}
 
 	return nil
 }
 
 // outputPruneBlobsJSON outputs the prune result as JSON
-func (v *Vaultik) outputPruneBlobsJSON(result *PruneBlobsResult) error {
-	encoder := json.NewEncoder(v.Stdout)
+func outputPruneBlobsJSON(result *PruneBlobsResult) error {
+	encoder := json.NewEncoder(os.Stdout)
 	encoder.SetIndent("", "  ")
 	return encoder.Encode(result)
 }

internal/vaultik/snapshot.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"regexp"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -86,7 +87,7 @@ func (v *Vaultik) CreateSnapshot(opts *SnapshotCreateOptions) error {
 
 	// Print overall summary if multiple snapshots
 	if len(snapshotNames) > 1 {
-		_, _ = fmt.Fprintf(v.Stdout, "\nAll %d snapshots completed in %s\n", len(snapshotNames), time.Since(overallStartTime).Round(time.Second))
+		v.printfStdout("\nAll %d snapshots completed in %s\n", len(snapshotNames), time.Since(overallStartTime).Round(time.Second))
 	}
 
 	return nil
@@ -99,7 +100,7 @@ func (v *Vaultik) createNamedSnapshot(opts *SnapshotCreateOptions, hostname, sna
 	snapConfig := v.Config.Snapshots[snapName]
 
 	if total > 1 {
-		_, _ = fmt.Fprintf(v.Stdout, "\n=== Snapshot %d/%d: %s ===\n", idx, total, snapName)
+		v.printfStdout("\n=== Snapshot %d/%d: %s ===\n", idx, total, snapName)
 	}
 
 	// Resolve source directories to absolute paths
@@ -152,7 +153,7 @@ func (v *Vaultik) createNamedSnapshot(opts *SnapshotCreateOptions, hostname, sna
 		return fmt.Errorf("creating snapshot: %w", err)
 	}
 	log.Info("Beginning snapshot", "snapshot_id", snapshotID, "name", snapName)
-	_, _ = fmt.Fprintf(v.Stdout, "Beginning snapshot: %s\n", snapshotID)
+	v.printfStdout("Beginning snapshot: %s\n", snapshotID)
 
 	for i, dir := range resolvedDirs {
 		// Check if context is cancelled
@@ -164,7 +165,7 @@ func (v *Vaultik) createNamedSnapshot(opts *SnapshotCreateOptions, hostname, sna
 		}
 
 		log.Info("Scanning directory", "path", dir)
-		_, _ = fmt.Fprintf(v.Stdout, "Beginning directory scan (%d/%d): %s\n", i+1, len(resolvedDirs), dir)
+		v.printfStdout("Beginning directory scan (%d/%d): %s\n", i+1, len(resolvedDirs), dir)
 		result, err := scanner.Scan(v.ctx, dir, snapshotID)
 		if err != nil {
 			return fmt.Errorf("failed to scan %s: %w", dir, err)
@@ -275,35 +276,35 @@ func (v *Vaultik) createNamedSnapshot(opts *SnapshotCreateOptions, hostname, sna
 	}
 
 	// Print comprehensive summary
-	_, _ = fmt.Fprintf(v.Stdout, "=== Snapshot Complete ===\n")
-	_, _ = fmt.Fprintf(v.Stdout, "ID: %s\n", snapshotID)
-	_, _ = fmt.Fprintf(v.Stdout, "Files: %s examined, %s to process, %s unchanged",
+	v.printfStdout("=== Snapshot Complete ===\n")
+	v.printfStdout("ID: %s\n", snapshotID)
+	v.printfStdout("Files: %s examined, %s to process, %s unchanged",
 		formatNumber(totalFiles),
 		formatNumber(totalFilesChanged),
 		formatNumber(totalFilesSkipped))
 	if totalFilesDeleted > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, ", %s deleted", formatNumber(totalFilesDeleted))
+		v.printfStdout(", %s deleted", formatNumber(totalFilesDeleted))
 	}
-	_, _ = fmt.Fprintln(v.Stdout)
-	_, _ = fmt.Fprintf(v.Stdout, "Data: %s total (%s to process)",
+	v.printlnStdout()
+	v.printfStdout("Data: %s total (%s to process)",
 		humanize.Bytes(uint64(totalBytesAll)),
 		humanize.Bytes(uint64(totalBytesChanged)))
 	if totalBytesDeleted > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, ", %s deleted", humanize.Bytes(uint64(totalBytesDeleted)))
+		v.printfStdout(", %s deleted", humanize.Bytes(uint64(totalBytesDeleted)))
 	}
-	_, _ = fmt.Fprintln(v.Stdout)
+	v.printlnStdout()
 	if totalBlobsUploaded > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, "Storage: %s compressed from %s (%.2fx)\n",
+		v.printfStdout("Storage: %s compressed from %s (%.2fx)\n",
 			humanize.Bytes(uint64(totalBlobSizeCompressed)),
 			humanize.Bytes(uint64(totalBlobSizeUncompressed)),
 			compressionRatio)
-		_, _ = fmt.Fprintf(v.Stdout, "Upload: %d blobs, %s in %s (%s)\n",
+		v.printfStdout("Upload: %d blobs, %s in %s (%s)\n",
 			totalBlobsUploaded,
 			humanize.Bytes(uint64(totalBytesUploaded)),
 			formatDuration(uploadDuration),
 			avgUploadSpeed)
 	}
-	_, _ = fmt.Fprintf(v.Stdout, "Duration: %s\n", formatDuration(snapshotDuration))
+	v.printfStdout("Duration: %s\n", formatDuration(snapshotDuration))
 
 	if opts.Prune {
 		log.Info("Pruning enabled - will delete old snapshots after snapshot")
@@ -527,14 +528,14 @@ func (v *Vaultik) PurgeSnapshots(keepLatest bool, olderThan string, force bool)
 	}
 
 	if len(toDelete) == 0 {
-		_, _ = fmt.Fprintln(v.Stdout, "No snapshots to delete")
+		v.printlnStdout("No snapshots to delete")
 		return nil
 	}
 
 	// Show what will be deleted
-	_, _ = fmt.Fprintf(v.Stdout, "The following snapshots will be deleted:\n\n")
+	v.printfStdout("The following snapshots will be deleted:\n\n")
 	for _, snap := range toDelete {
-		_, _ = fmt.Fprintf(v.Stdout, "  %s (%s, %s)\n",
+		v.printfStdout("  %s (%s, %s)\n",
 			snap.ID,
 			snap.Timestamp.Format("2006-01-02 15:04:05"),
 			formatBytes(snap.CompressedSize))
@@ -542,19 +543,19 @@ func (v *Vaultik) PurgeSnapshots(keepLatest bool, olderThan string, force bool)
 
 	// Confirm unless --force is used
 	if !force {
-		_, _ = fmt.Fprintf(v.Stdout, "\nDelete %d snapshot(s)? [y/N] ", len(toDelete))
+		v.printfStdout("\nDelete %d snapshot(s)? [y/N] ", len(toDelete))
 		var confirm string
-		if _, err := fmt.Fscanln(v.Stdin, &confirm); err != nil {
+		if _, err := fmt.Scanln(&confirm); err != nil {
 			// Treat EOF or error as "no"
-			_, _ = fmt.Fprintln(v.Stdout, "Cancelled")
+			v.printlnStdout("Cancelled")
 			return nil
 		}
 		if strings.ToLower(confirm) != "y" {
-			_, _ = fmt.Fprintln(v.Stdout, "Cancelled")
+			v.printlnStdout("Cancelled")
 			return nil
 		}
 	} else {
-		_, _ = fmt.Fprintf(v.Stdout, "\nDeleting %d snapshot(s) (--force specified)\n", len(toDelete))
+		v.printfStdout("\nDeleting %d snapshot(s) (--force specified)\n", len(toDelete))
 	}
 
 	// Delete snapshots (both local and remote)
@@ -569,10 +570,10 @@ func (v *Vaultik) PurgeSnapshots(keepLatest bool, olderThan string, force bool)
 		}
 	}
 
-	_, _ = fmt.Fprintf(v.Stdout, "Deleted %d snapshot(s)\n", len(toDelete))
+	v.printfStdout("Deleted %d snapshot(s)\n", len(toDelete))
 
 	// Note: Run 'vaultik prune' separately to clean up unreferenced blobs
-	_, _ = fmt.Fprintln(v.Stdout, "\nNote: Run 'vaultik prune' to clean up unreferenced blobs.")
+	v.printlnStdout("\nNote: Run 'vaultik prune' to clean up unreferenced blobs.")
 
 	return nil
 }
@@ -613,11 +614,11 @@ func (v *Vaultik) VerifySnapshotWithOptions(snapshotID string, opts *VerifyOptio
 	}
 
 	if !opts.JSON {
-		_, _ = fmt.Fprintf(v.Stdout, "Verifying snapshot %s\n", snapshotID)
+		v.printfStdout("Verifying snapshot %s\n", snapshotID)
 		if !snapshotTime.IsZero() {
-			_, _ = fmt.Fprintf(v.Stdout, "Snapshot time: %s\n", snapshotTime.Format("2006-01-02 15:04:05 MST"))
+			v.printfStdout("Snapshot time: %s\n", snapshotTime.Format("2006-01-02 15:04:05 MST"))
 		}
-		fmt.Println()
+		v.printlnStdout()
 	}
 
 	// Download and parse manifest
@@ -635,18 +636,18 @@ func (v *Vaultik) VerifySnapshotWithOptions(snapshotID string, opts *VerifyOptio
 	result.TotalSize = manifest.TotalCompressedSize
 
 	if !opts.JSON {
-		_, _ = fmt.Fprintf(v.Stdout, "Snapshot information:\n")
-		_, _ = fmt.Fprintf(v.Stdout, "  Blob count:   %d\n", manifest.BlobCount)
-		_, _ = fmt.Fprintf(v.Stdout, "  Total size:   %s\n", humanize.Bytes(uint64(manifest.TotalCompressedSize)))
+		v.printfStdout("Snapshot information:\n")
+		v.printfStdout("  Blob count:   %d\n", manifest.BlobCount)
+		v.printfStdout("  Total size:   %s\n", humanize.Bytes(uint64(manifest.TotalCompressedSize)))
 		if manifest.Timestamp != "" {
 			if t, err := time.Parse(time.RFC3339, manifest.Timestamp); err == nil {
-				_, _ = fmt.Fprintf(v.Stdout, "  Created:      %s\n", t.Format("2006-01-02 15:04:05 MST"))
+				v.printfStdout("  Created:      %s\n", t.Format("2006-01-02 15:04:05 MST"))
 			}
 		}
-		_, _ = fmt.Fprintln(v.Stdout)
+		v.printlnStdout()
 
 		// Check each blob exists
-		_, _ = fmt.Fprintf(v.Stdout, "Checking blob existence...\n")
+		v.printfStdout("Checking blob existence...\n")
 	}
 
 	missing := 0
@@ -660,7 +661,7 @@ func (v *Vaultik) VerifySnapshotWithOptions(snapshotID string, opts *VerifyOptio
 		_, err := v.Storage.Stat(v.ctx, blobPath)
 		if err != nil {
 			if !opts.JSON {
-				_, _ = fmt.Fprintf(v.Stdout, "  Missing: %s (%s)\n", blob.Hash, humanize.Bytes(uint64(blob.CompressedSize)))
+				v.printfStdout("  Missing: %s (%s)\n", blob.Hash, humanize.Bytes(uint64(blob.CompressedSize)))
 			}
 			missing++
 			missingSize += blob.CompressedSize
@@ -683,20 +684,20 @@ func (v *Vaultik) VerifySnapshotWithOptions(snapshotID string, opts *VerifyOptio
 		return v.outputVerifyJSON(result)
 	}
 
-	_, _ = fmt.Fprintf(v.Stdout, "\nVerification complete:\n")
-	_, _ = fmt.Fprintf(v.Stdout, "  Verified:     %d blobs (%s)\n", verified,
+	v.printfStdout("\nVerification complete:\n")
+	v.printfStdout("  Verified:     %d blobs (%s)\n", verified,
 		humanize.Bytes(uint64(manifest.TotalCompressedSize-missingSize)))
 	if missing > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, "  Missing:      %d blobs (%s)\n", missing, humanize.Bytes(uint64(missingSize)))
+		v.printfStdout("  Missing:      %d blobs (%s)\n", missing, humanize.Bytes(uint64(missingSize)))
 	} else {
-		_, _ = fmt.Fprintf(v.Stdout, "  Missing:      0 blobs\n")
+		v.printfStdout("  Missing:      0 blobs\n")
 	}
-	_, _ = fmt.Fprintf(v.Stdout, "  Status:       ")
+	v.printfStdout("  Status:       ")
 	if missing > 0 {
-		_, _ = fmt.Fprintf(v.Stdout, "FAILED - %d blobs are missing\n", missing)
+		v.printfStdout("FAILED - %d blobs are missing\n", missing)
 		return fmt.Errorf("%d blobs are missing", missing)
 	} else {
-		_, _ = fmt.Fprintf(v.Stdout, "OK - All blobs verified\n")
+		v.printfStdout("OK - All blobs verified\n")
 	}
 
 	return nil
@@ -830,11 +831,11 @@ func (v *Vaultik) RemoveSnapshot(snapshotID string, opts *RemoveOptions) (*Remov
 	if opts.DryRun {
 		result.DryRun = true
 		if !opts.JSON {
-			_, _ = fmt.Fprintf(v.Stdout, "Would remove snapshot: %s\n", snapshotID)
+			v.printfStdout("Would remove snapshot: %s\n", snapshotID)
 			if opts.Remote {
-				_, _ = fmt.Fprintln(v.Stdout, "Would also remove from remote storage")
+				v.printlnStdout("Would also remove from remote storage")
 			}
-			_, _ = fmt.Fprintln(v.Stdout, "[Dry run - no changes made]")
+			v.printlnStdout("[Dry run - no changes made]")
 		}
 		if opts.JSON {
 			return result, v.outputRemoveJSON(result)
@@ -845,17 +846,17 @@ func (v *Vaultik) RemoveSnapshot(snapshotID string, opts *RemoveOptions) (*Remov
 	// Confirm unless --force is used (skip in JSON mode - require --force)
 	if !opts.Force && !opts.JSON {
 		if opts.Remote {
-			_, _ = fmt.Fprintf(v.Stdout, "Remove snapshot '%s' from local database and remote storage? [y/N] ", snapshotID)
+			v.printfStdout("Remove snapshot '%s' from local database and remote storage? [y/N] ", snapshotID)
 		} else {
-			_, _ = fmt.Fprintf(v.Stdout, "Remove snapshot '%s' from local database? [y/N] ", snapshotID)
+			v.printfStdout("Remove snapshot '%s' from local database? [y/N] ", snapshotID)
 		}
 		var confirm string
-		if _, err := fmt.Fscanln(v.Stdin, &confirm); err != nil {
-			_, _ = fmt.Fprintln(v.Stdout, "Cancelled")
+		if err := v.scanlnStdin(&confirm); err != nil {
+			v.printlnStdout("Cancelled")
 			return result, nil
 		}
 		if strings.ToLower(confirm) != "y" {
-			_, _ = fmt.Fprintln(v.Stdout, "Cancelled")
+			v.printlnStdout("Cancelled")
 			return result, nil
 		}
 	}
@@ -882,10 +883,10 @@ func (v *Vaultik) RemoveSnapshot(snapshotID string, opts *RemoveOptions) (*Remov
 	}
 
 	// Print summary
-	_, _ = fmt.Fprintf(v.Stdout, "Removed snapshot '%s' from local database\n", snapshotID)
+	v.printfStdout("Removed snapshot '%s' from local database\n", snapshotID)
 	if opts.Remote {
-		_, _ = fmt.Fprintln(v.Stdout, "Removed snapshot metadata from remote storage")
-		_, _ = fmt.Fprintln(v.Stdout, "\nNote: Blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
+		v.printlnStdout("Removed snapshot metadata from remote storage")
+		v.printlnStdout("\nNote: Blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
 	}
 
 	return result, nil
@@ -929,7 +930,7 @@ func (v *Vaultik) RemoveAllSnapshots(opts *RemoveOptions) (*RemoveResult, error)
 
 	if len(snapshotIDs) == 0 {
 		if !opts.JSON {
-			_, _ = fmt.Fprintln(v.Stdout, "No snapshots found")
+			v.printlnStdout("No snapshots found")
 		}
 		return result, nil
 	}
@@ -938,14 +939,14 @@ func (v *Vaultik) RemoveAllSnapshots(opts *RemoveOptions) (*RemoveResult, error)
 		result.DryRun = true
 		result.SnapshotsRemoved = snapshotIDs
 		if !opts.JSON {
-			_, _ = fmt.Fprintf(v.Stdout, "Would remove %d snapshot(s):\n", len(snapshotIDs))
+			v.printfStdout("Would remove %d snapshot(s):\n", len(snapshotIDs))
 			for _, id := range snapshotIDs {
-				_, _ = fmt.Fprintf(v.Stdout, "  %s\n", id)
+				v.printfStdout("  %s\n", id)
 			}
 			if opts.Remote {
-				_, _ = fmt.Fprintln(v.Stdout, "Would also remove from remote storage")
+				v.printlnStdout("Would also remove from remote storage")
 			}
-			_, _ = fmt.Fprintln(v.Stdout, "[Dry run - no changes made]")
+			v.printlnStdout("[Dry run - no changes made]")
 		}
 		if opts.JSON {
 			return result, v.outputRemoveJSON(result)
@@ -986,10 +987,10 @@ func (v *Vaultik) RemoveAllSnapshots(opts *RemoveOptions) (*RemoveResult, error)
 		return result, v.outputRemoveJSON(result)
 	}
 
-	_, _ = fmt.Fprintf(v.Stdout, "Removed %d snapshot(s)\n", len(result.SnapshotsRemoved))
+	v.printfStdout("Removed %d snapshot(s)\n", len(result.SnapshotsRemoved))
 	if opts.Remote {
-		_, _ = fmt.Fprintln(v.Stdout, "Removed snapshot metadata from remote storage")
-		_, _ = fmt.Fprintln(v.Stdout, "\nNote: Blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
+		v.printlnStdout("Removed snapshot metadata from remote storage")
+		v.printlnStdout("\nNote: Blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
 	}
 
 	return result, nil
@@ -1117,21 +1118,29 @@ func (v *Vaultik) PruneDatabase() (*PruneResult, error) {
 	)
 
 	// Print summary
-	_, _ = fmt.Fprintf(v.Stdout, "Local database prune complete:\n")
-	_, _ = fmt.Fprintf(v.Stdout, "  Incomplete snapshots removed: %d\n", result.SnapshotsDeleted)
-	_, _ = fmt.Fprintf(v.Stdout, "  Orphaned files removed: %d\n", result.FilesDeleted)
-	_, _ = fmt.Fprintf(v.Stdout, "  Orphaned chunks removed: %d\n", result.ChunksDeleted)
-	_, _ = fmt.Fprintf(v.Stdout, "  Orphaned blobs removed: %d\n", result.BlobsDeleted)
+	v.printfStdout("Local database prune complete:\n")
+	v.printfStdout("  Incomplete snapshots removed: %d\n", result.SnapshotsDeleted)
+	v.printfStdout("  Orphaned files removed: %d\n", result.FilesDeleted)
+	v.printfStdout("  Orphaned chunks removed: %d\n", result.ChunksDeleted)
+	v.printfStdout("  Orphaned blobs removed: %d\n", result.BlobsDeleted)
 
 	return result, nil
 }
 
-// getTableCount returns the count of rows in a table
+// validTableNameRe matches table names containing only lowercase alphanumeric characters and underscores.
+var validTableNameRe = regexp.MustCompile(`^[a-z0-9_]+$`)
+
+// getTableCount returns the count of rows in a table.
+// The tableName is sanitized to only allow [a-z0-9_] characters to prevent SQL injection.
 func (v *Vaultik) getTableCount(tableName string) (int64, error) {
 	if v.DB == nil {
 		return 0, nil
 	}
 
+	if !validTableNameRe.MatchString(tableName) {
+		return 0, fmt.Errorf("invalid table name: %q", tableName)
+	}
+
 	var count int64
 	query := fmt.Sprintf("SELECT COUNT(*) FROM %s", tableName)
 	err := v.DB.Conn().QueryRowContext(v.ctx, query).Scan(&count)