Viewing compression ratios on DoubleSpace/DriveSpace disks Which DIR option displays a column showing the compression ratio for each file (feature introduced in DOS 6.00)?

Introduction / Context:
DOS 6.x introduced disk compression utilities (DoubleSpace/DriveSpace) and enhanced DIR options to display per-file compression information. This helps users assess savings and identify unusually large or poorly compressed files when managing limited storage.

Given Data / Assumptions:

• The system is DOS 6.00 or later with compression features enabled.
• We want a DIR switch that adds a compression column.
• Other DIR switches alter format (wide, bare) or include recursion.

Concept / Approach:

DIR /C augments the listing to include compression ratios for each file when using DoubleSpace/DriveSpace. This is distinct from listing styles or recursion depth. The switch acts as a reporting aid, not a compression action by itself.

Step-by-Step Solution:

Verification / Alternative check:

Run DIR with and without /C on a compressed volume; observe that the additional column appears only when /C is used and the volume supports compression stats.

Why Other Options Are Wrong:

a: /W uses wide format; no compression column.

b: /S includes subdirectories; still no compression column.

c: /B shows bare names; it removes extra columns entirely.

e: Not applicable because /C is correct for compression ratio display.

Common Pitfalls:

Expecting /C to compress files; it only reports ratios. On uncompressed volumes, the column may not be meaningful.

Final Answer:

DIR /C