Sorting text in DOS — reversing alphabetical order: Which DOS command line correctly sorts the contents of a file in reverse order and sends the result to the screen (or can be redirected)?

Introduction / Context:
The DOS SORT filter reads from standard input and writes sorted text to standard output. Mastering its switches lets you quickly reorder data without external tools. Reversing the sort requires a specific flag.

Given Data / Assumptions:

• The input is a text file, referenced via standard input redirection.
• We want reverse (descending) sort order.
• We are using the native DOS SORT options.

Concept / Approach:

By default, SORT sorts ascending. The /R switch reverses the sort order. DOS typically uses redirection (<) to feed a file into SORT. Therefore, the correct pattern is SORT /R < filename. You can also redirect output to a new file with > out.txt if needed.

Step-by-Step Solution:

Verification / Alternative check:

Typing SORT /? in DOS lists switches; /R is documented as reverse sort order. Test with a small file to observe reversed output.

Why Other Options Are Wrong:

• SORT > filename: attempts to write SORT's output but provides no input; it does not reverse order.
• SORT < filename: correct for ascending, but not reverse.
• SORT /V: not a standard reverse-order switch in DOS SORT.
• None of the above: incorrect because a correct solution exists.

Common Pitfalls:

Forgetting redirection, assuming SORT takes the filename as a direct argument in all DOS versions; omitting /R and wondering why the order is ascending.

Final Answer:

SORT /R < filename