You have site.tar.gz in your home directory and need its contents unpacked under /opt/site, without changing your working directory first. Which command does that?
LPIC-1 Exam 101-500, objective 103. GNU and Unix commands medium
Machine-checked — no person has signed for it. This question was read against the source cited below by an automated pass, which found no contradiction. That is a weaker claim than it sounds: the same kind of process wrote the question, so it can confirm its own mistake.
Treat it as a good draft rather than as settled fact, and read the source below before you rely on it. It is not used in mock exams here — only questions a person has signed for are.
How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Correct tar -xzf site.tar.gz -C /opt/site
Correct. -C changes to the named directory before extracting, so the archive's paths are created relative to /opt/site while the archive itself is still read from the current directory.
Not correct tar -xzf site.tar.gz /opt/site
Wrong. A non-option argument after the archive name is a member to extract, so tar looks for a stored path called opt/site and reports that it is not found in the archive.
Not correct tar -xzf site.tar.gz > /opt/site
Wrong. Extraction writes files itself and prints nothing to stdout, so the redirection merely creates or truncates a file named /opt/site while the members land in the current directory.
Not correct tar -czf site.tar.gz -C /opt/site
Wrong. -c creates an archive instead of extracting one, and -C is followed by no member names, so there is nothing to archive: GNU tar stops with "Cowardly refusing to create an empty archive" before it ever opens the output file.
Why
The three mutually exclusive tar modes are -c create, -x extract and -t list, combined with -f to name the archive file and a compression selector: -z for gzip, -j for bzip2, -J for xz. -C DIR applies at the point it appears on the command line, so it can be used to change directory before extracting or, when creating, before the file names that follow it are read.
Where this comes from
- Cited
- manual page tar(1)
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 103 and space the ones you get wrong.
More questions on this objective
- A user starts a new terminal window in a running graphical desktop session, which launches bash as an interactive shell that is NOT a login shell. Which file in the user's home directory does bash read in that case? machine-checked
- In bash, which history expansion re-runs the entire previous command line? machine-checked
- Which bash command prints the literal five characters $USER instead of the current user name? machine-checked
- You want /opt/bin searched for executables, after all the directories already in PATH, in the current bash session and in every command started from it. Which command does that? machine-checked
- There is a passwd manual page in section 1 (the command) and another in section 5 (the /etc/passwd file format). Which command opens the section 5 page? machine-checked
- Select the TWO true statements about shell variables and the environment in bash. machine-checked