cmd: move function copyFile into utils.go

cmd/bbolt/surgery_commands.go

@@ -4,8 +4,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io"
-	"os"
 	"strconv"
 	"strings"
 
@@ -64,22 +62,6 @@ func (cmd *surgeryCommand) parsePathsAndCopyFile(fs *flag.FlagSet) error {
 		return errors.New("output file required")
 	}
 
-	// Ensure source file exists.
-	_, err := os.Stat(cmd.srcPath)
-	if os.IsNotExist(err) {
-		return ErrFileNotFound
-	} else if err != nil {
-		return err
-	}
-
-	// Ensure output file not exist.
-	_, err = os.Stat(cmd.dstPath)
-	if err == nil {
-		return fmt.Errorf("output file %q already exists", cmd.dstPath)
-	} else if !os.IsNotExist(err) {
-		return err
-	}
-
 	// Copy database from SrcPath to DstPath
 	if err := copyFile(cmd.srcPath, cmd.dstPath); err != nil {
 		return fmt.Errorf("failed to copy file: %w", err)
@@ -88,34 +70,6 @@ func (cmd *surgeryCommand) parsePathsAndCopyFile(fs *flag.FlagSet) error {
 	return nil
 }
 
-func copyFile(srcPath, dstPath string) error {
-	srcDB, err := os.Open(srcPath)
-	if err != nil {
-		return fmt.Errorf("failed to open source file %q: %w", srcPath, err)
-	}
-	defer srcDB.Close()
-	dstDB, err := os.Create(dstPath)
-	if err != nil {
-		return fmt.Errorf("failed to create output file %q: %w", dstPath, err)
-	}
-	defer dstDB.Close()
-	written, err := io.Copy(dstDB, srcDB)
-	if err != nil {
-		return fmt.Errorf("failed to copy database file from %q to %q: %w", srcPath, dstPath, err)
-	}
-
-	srcFi, err := srcDB.Stat()
-	if err != nil {
-		return fmt.Errorf("failed to get source file info %q: %w", srcPath, err)
-	}
-	initialSize := srcFi.Size()
-	if initialSize != written {
-		return fmt.Errorf("the byte copied (%q: %d) isn't equal to the initial db size (%q: %d)", dstPath, written, srcPath, initialSize)
-	}
-
-	return nil
-}
-
 // Usage returns the help message.
 func (cmd *surgeryCommand) Usage() string {
 	return strings.TrimLeft(`

cmd/bbolt/utils.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+func copyFile(srcPath, dstPath string) error {
+	// Ensure source file exists.
+	_, err := os.Stat(srcPath)
+	if os.IsNotExist(err) {
+		return ErrFileNotFound
+	} else if err != nil {
+		return err
+	}
+
+	// Ensure output file not exist.
+	_, err = os.Stat(dstPath)
+	if err == nil {
+		return fmt.Errorf("output file %q already exists", dstPath)
+	} else if !os.IsNotExist(err) {
+		return err
+	}
+
+	srcDB, err := os.Open(srcPath)
+	if err != nil {
+		return fmt.Errorf("failed to open source file %q: %w", srcPath, err)
+	}
+	defer srcDB.Close()
+	dstDB, err := os.Create(dstPath)
+	if err != nil {
+		return fmt.Errorf("failed to create output file %q: %w", dstPath, err)
+	}
+	defer dstDB.Close()
+	written, err := io.Copy(dstDB, srcDB)
+	if err != nil {
+		return fmt.Errorf("failed to copy database file from %q to %q: %w", srcPath, dstPath, err)
+	}
+
+	srcFi, err := srcDB.Stat()
+	if err != nil {
+		return fmt.Errorf("failed to get source file info %q: %w", srcPath, err)
+	}
+	initialSize := srcFi.Size()
+	if initialSize != written {
+		return fmt.Errorf("the byte copied (%q: %d) isn't equal to the initial db size (%q: %d)", dstPath, written, srcPath, initialSize)
+	}
+
+	return nil
+}