On Unix/Linux, which command compares two files byte by byte to report the first difference or confirm they are identical?

Introduction / Context:
File comparison is a routine task in system administration and software development. While 'diff' shows line-by-line textual changes, sometimes you need a raw, byte-level comparison to validate copies, downloads, or binary artifacts. Unix provides a minimalist tool for this exact purpose.

Given Data / Assumptions:

• You have two files that may be identical or differ in binary content.
• You need a simple pass/fail or the first differing location.
• Human-friendly patches are not required.

Concept / Approach:
The 'cmp' command compares files byte by byte. With no options, it is silent if files match and reports the first byte/line where they differ if not. It is ideal for verifying integrity after copies, especially for binaries, images, and archives where textual diffs are not meaningful.

Step-by-Step Solution:

Verification / Alternative check:
Compare 'sha256sum file1 file2' to confirm identical hashes. When both 'cmp' and hash agree, integrity is assured.

Why Other Options Are Wrong:

• comp: DOS/Windows utility, not the standard Unix tool.
• do / ccp: Not file comparison commands on Unix/Linux.
• None of the above: Incorrect because 'cmp' is correct.

Common Pitfalls:
Using 'diff' for binaries (noisy/less useful), or forgetting that 'cmp' stops at the first difference (not a full difference report).

Final Answer:
cmp