Copying and renaming a file between directories (Unix cp): Which command copies the file 'wb' from the 'programs' directory to the 'misc' directory, naming the destination file 'wbx'?
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Acopy programs/wb misc/wbx
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Bcp programs/wb misc/wbx
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Ctar programs/wb misc/wbx
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Dcopy a:programs/wb b:misc/wbx
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ENone of the above
Answer
Correct Answer: cp programs/wb misc/wbx
Explanation
Introduction / Context:File management on Unix commonly involves copying files between directories and optionally renaming them in the process. The cp utility provides a simple syntax to specify a source path and a destination path that may include a new filename.
Given Data / Assumptions:
- Source file: programs/wb (relative path).
- Destination directory: misc/ with a new filename wbx.
- Standard POSIX cp behavior is assumed.
Concept / Approach:
The cp command takes the form cp source destination. If destination refers to a directory, cp copies into that directory with the same filename; if destination includes a trailing filename, the file is copied and simultaneously renamed. This is ideal for duplicating and renaming in one step.
Step-by-Step Solution:
Choose the correct utility: cp (copy in Unix).Specify relative source path: programs/wb.Specify destination path and new name: misc/wbx.Final command: cp programs/wb misc/wbxVerification / Alternative check:
After running the command, ls -l misc/wbx should list the new file. The original programs/wb remains unchanged. Optionally, compare checksums with sum or md5sum to confirm identity.
Why Other Options Are Wrong:
- copy programs/wb misc/wbx: 'copy' is a DOS command, not standard on Unix.
- tar programs/wb misc/wbx: tar creates/extracts archives; it does not copy single files in this manner.
- copy a:programs/wb b:misc/wbx: DOS drive-letter syntax; not applicable to Unix paths.
- None of the above: Incorrect because cp programs/wb misc/wbx is correct.
Common Pitfalls:
Forgetting quotes when paths contain spaces; overwriting existing files unintentionally (use cp -i for interactive prompts). For recursive directory copies, use cp -r, but for single files the basic cp is sufficient.
Final Answer:
cp programs/wb misc/wbx