Unrar Switch to Rename Files to Lowercase

When extracting files from a RAR archive, maintaining uniform file naming conventions across operating systems can prevent path errors and script failures. This article explains which command-line switch forces the unrar utility to automatically convert all extracted file and directory names to lowercase, along with standard command examples for direct implementation.

The Lowercase Switch: -cl

The switch that forces unrar to convert all extracted file and folder names to lowercase is -cl.

When included in your command, -cl intercepts the original names stored inside the archive header and writes them to the disk entirely in lower case, regardless of how they were capitalized when the archive was created.

Syntax and Usage

The -cl switch works with both full-path extraction (x) and flat extraction (e).

1. Extract with Full Directory Paths

To extract all contents, preserve the directory hierarchy, and convert every file and folder name to lowercase:

unrar x -cl archive.rar /path/to/destination/

2. Extract Without Directory Paths (Flat)

To unpack all files directly into the target folder without creating subdirectories, while making all filenames lowercase:

unrar e -cl archive.rar /path/to/destination/

Important Considerations

• Case Sensitivity on Linux/macOS: Unlike Windows, Linux and macOS (on case-sensitive filesystems) treat FILE.TXT and file.txt as distinct files. If an archive contains two files in the same directory that differ only by case (e.g., Test.txt and test.txt), applying -cl will cause a naming collision, prompting unrar to overwrite or skip the second file.
• Opposite Switch (-cu): If you ever need the inverse behavior, the -cu switch forces all extracted filenames to uppercase.