Linux/UNIX file listing: Which command lists all files whose names end with the extension “.lst”, showing a detailed long listing for each match?

Introduction / Context:Command-line globbing patterns are crucial for filtering files by name. In Linux/UNIX shells, the asterisk * and other special characters expand to sets of filenames before the command runs. The ls utility then lists those files. Understanding which pattern truly selects files with a specific extension avoids accidental matches and incorrect outputs.

Given Data / Assumptions:

• You want only filenames ending in “.lst”.
• You also want a long listing (permissions, ownership, size, timestamps).
• Globbing is performed by the shell, not by ls itself.

Concept / Approach:The pattern “.lst” matches any file whose basename ends in the literal characters “.lst”. The ls -l flag produces a long listing. Other patterns here either select different names or are malformed for the stated goal. Therefore, “ls -l *.lst” precisely expresses “detailed listing of all .lst files.”

Step-by-Step Solution:

Verification / Alternative check:Run “echo *.lst” to see expanded matches. Compare “ls .lst” (short listing) versus “ls -l .lst” (long listing) to verify output differences.

Why Other Options Are Wrong:ls lst: matches names beginning with “lst”, not ending in “.lst”. ls .: matches names with any dot, far broader than “.lst”. ls [lst]: matches names ending in one of the characters l, s, or t, not the string “.lst”. None of the above: incorrect because option A is correct.

Common Pitfalls:Quoting the pattern (e.g., ".lst") prevents shell expansion when not desired; forgetting that hidden files (starting with a dot) are not matched by “” unless your shell option dotglob is set.

Final Answer:ls -l *.lst