Unrar Overwrite Only If Newer Switch

When extracting files using the command-line utility unrar, you can prevent unnecessary file replacements by restricting overwrites to files that are newer in the archive. This article explains the exact command-line switches required—specifically the -u (Update) and -f (Freshen) switches—and demonstrates how to run them to update destination files safely.

The Primary Switch: -u (Update)

The switch that tells unrar to overwrite files only if the archived file is newer is -u.

When applied to an extraction command, -u performs an "update" operation:

• It extracts files that do not exist yet in the destination directory.
• It overwrites existing files only if the file inside the RAR archive has a more recent modification timestamp than the local file.
• It leaves newer or identical existing local files untouched.

Usage Example

To extract an archive with full directory paths while updating only older files:

unrar x -u archive.rar

To extract directly into the current working directory without recreating internal archive paths:

unrar e -u archive.rar

The Alternative Switch: -f (Freshen)

If your goal is to overwrite older files without extracting any new files that do not already exist on disk, use the -f (Freshen) switch.

• It checks files in the target directory that share names with files in the archive.
• It overwrites them only if the archived copy is newer.
• Unlike -u, it skips any files in the archive that do not already exist in the target folder.

Usage Example

unrar x -f archive.rar

Summary of Extraction Behavior