Which UNIX command is used to display a file's contents in octal (and other base) representations?

Introduction / Context:
Inspecting raw file data is a common need when debugging encodings, binary formats, or control characters. UNIX provides tools to dump file contents in octal, hexadecimal, and ASCII, enabling byte-level verification independent of text encodings or editors.

Given Data / Assumptions:

• We need a standard utility to output bytes numerically.
• Compatibility with POSIX environments is implied.
• Command should support octal natively.

Concept / Approach:

od stands for “octal dump.” It can print data in octal by default and also in hex or character formats using options (e.g., -t x1 for hex bytes, -c for characters). The other choices are not standard UNIX utilities for octal dumps: cd changes directories; of and oct are not standard commands.

Step-by-Step Solution:

Verification / Alternative check:

Running od -c /bin/sh | head demonstrates character and octal output, confirming the command's purpose.

Why Other Options Are Wrong:

• cd: directory navigation only.
• of, oct: nonstandard/incorrect command names.
• None of the above: incorrect because od is correct.

Common Pitfalls:

• Misreading base; use -t to specify exact type and width.
• Forgetting to suppress addresses with -An when parsing programmatically.

Final Answer:

od.