Update ToolCopy over a new version of a file only if there are changes.
- update - conditionally update target file.
- update [OPTIONS] FILE
update reads input from a pipe or file and saves it to a target (FILE) if there are changes. If the new content is the same as the old, the target is left untouched. By default, the target is also left untouched if the new content is empty. There are options to also abstain from applying an update if the changes are too large, and to back up the previous version.
The purpose is to handle files with dynamically generated content in such a manner that timestamps don't change if the content doesn't change, and mistakes in content generation doesn't unnecessarily propa- gate to the target.
Henrik Levkowetz <email@example.com>