fsutil

func CopyFileAtomic ¶

func CopyFileAtomic(src, dst string) error

CopyFileAtomic performs an atomic streaming copy from src to dst. It writes to a temporary file first, then renames it to the destination. This ensures the destination file is never in a partially written state.

Features:

• Streaming copy (memory-safe for large files)
• Atomic rename (most filesystems)
• Automatic cleanup of temp files on error
• Preserves source file permissions
• Unique temp filenames (safe for concurrent writes to same destination)

Returns an error if any operation fails (open, copy, close, rename).