gzip and gunzip in Linux CLI - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this gzip command?

You have a file named example.txt containing the text Hello World. You run the command gzip example.txt. What happens to the files in the directory?

A A new file <code>example.txt.gz</code> is created, but <code>example.txt</code> remains unchanged.

B The command fails with an error because <code>example.txt</code> is not empty.

C The command outputs the content of <code>example.txt</code> compressed to the terminal.

D The file <code>example.txt</code> is replaced by <code>example.txt.gz</code> containing compressed data, and <code>example.txt</code> no longer exists.

💡 Hint

Think about what gzip does by default to the original file after compression.

By default, gzip compresses the file and replaces the original file with the compressed version having a .gz extension.

💻 Command Output

intermediate

What is the output of this gunzip command?

You have a compressed file archive.gz. You run gunzip archive.gz. What happens to the files in the directory?

A The file <code>archive.gz</code> is decompressed to <code>archive</code>, and <code>archive.gz</code> is deleted.

B The file <code>archive.gz</code> remains, and a new file <code>archive</code> is created.

C The command outputs the decompressed content to the terminal without creating any file.

D The command fails because <code>archive.gz</code> is read-only.

💡 Hint

Consider what gunzip does by default to the compressed file after decompression.

gunzip decompresses the file and removes the original .gz file by default.

📝 Syntax

advanced

Which command correctly compresses multiple files into one gzip archive?

You want to compress files file1.txt and file2.txt into a single compressed file named files.gz. Which command achieves this?

A gzip -c file1.txt file2.txt > files.gz

B gzip -d file1.txt file2.txt > files.gz

C gzip file1.txt file2.txt -c > files.gz

D gzip -r files.gz file1.txt file2.txt

💡 Hint

gzip alone compresses single files; to combine multiple files, use the -c option and redirect output.

Using 'gzip -c file1.txt file2.txt > files.gz' compresses both files' contents into one gzip stream saved as files.gz.

💻 Command Output

advanced

What error does this command produce?

You run gunzip -c missingfile.gz but the file missingfile.gz does not exist. What is the output?

A gunzip: cannot open missingfile.gz: Permission denied

B gunzip: missingfile.gz: No such file or directory

C gunzip: missingfile.gz: File format not recognized

D gunzip: missingfile.gz: Already decompressed

💡 Hint

Think about what happens when a command tries to access a file that does not exist.

The error message indicates the file is missing, so gunzip cannot open it.

🚀 Application

expert

How to decompress a gzip file and save output to a different file?

You have a compressed file data.gz. You want to decompress it but save the output to output.txt without deleting data.gz. Which command achieves this?

A gunzip data.gz -o output.txt

B gunzip data.gz > output.txt

C gunzip -c data.gz > output.txt

D gzip -d data.gz -c > output.txt

💡 Hint

Use an option that decompresses to standard output without removing the original file.

The -c option decompresses to stdout, so redirecting output saves it to a new file without deleting the original.

Practice

1. What does the gzip command do in Linux?

easy

A. Lists files in a directory

B. Deletes a file permanently

C. Compresses a file and replaces the original with a .gz file

D. Creates a backup copy of a file

Solution

1. Step 1: Understand gzip purpose

   The gzip command compresses files to save disk space.

2. Step 2: Effect on original file

   It replaces the original file with a compressed file ending in .gz.

3. Final Answer:

   Compresses a file and replaces the original with a .gz file -> Option C

4. Quick Check:

   gzip compresses files = D [OK]

Hint: gzip compresses and replaces original file by default [OK]

Common Mistakes:

• Thinking gzip deletes files without compression
• Confusing gzip with backup commands
• Assuming gzip lists files

2. Which of the following is the correct syntax to compress a file named data.txt but keep the original file?

easy

A. gzip data.txt

B. gzip -d data.txt

C. gunzip -k data.txt

D. gzip -k data.txt

Solution

1. Step 1: Identify option to keep original

   The -k option tells gzip to keep the original file after compression.

2. Step 2: Match correct command

   gzip -k data.txt compresses and keeps the original file.

3. Final Answer:

   gzip -k data.txt -> Option D

4. Quick Check:

   Use -k to keep original file [OK]

Hint: Use -k with gzip to keep original file [OK]

Common Mistakes:

• Using gunzip instead of gzip for compression
• Using -d which is for decompression
• Not using -k and losing original file

3. What will be the output of the following commands?

gzip -k report.txt
gunzip report.txt.gz

medium

A. Only report.txt exists after commands

B. Both report.txt and report.txt.gz exist after commands

C. Original report.txt deleted, only report.txt.gz remains

D. Error because gunzip cannot decompress .gz files

Solution

1. Step 1: Analyze gzip -k report.txt

   This compresses report.txt to report.txt.gz and keeps the original report.txt file.

2. Step 2: Analyze gunzip report.txt.gz

   This decompresses report.txt.gz back to report.txt and deletes the .gz file.

3. Final Answer:

   Only report.txt exists after commands -> Option A

4. Quick Check:

   gzip -k keeps original, gunzip restores and removes .gz [OK]

Hint: gunzip removes .gz file after decompression [OK]

Common Mistakes:

• Assuming gzip deletes original with -k option
• Thinking gunzip keeps .gz file after decompression
• Confusing gzip and gunzip roles

4. You run gunzip file.txt but get an error saying "not in gzip format." What is the likely problem?

medium

A. gunzip command is misspelled

B. file.txt is not a compressed .gz file

C. file.txt is already decompressed

D. You need to use gzip instead of gunzip

Solution

1. Step 1: Understand gunzip input requirement

   gunzip expects a file compressed with gzip, usually ending with .gz.

2. Step 2: Analyze error message

   "not in gzip format" means the file is not compressed or not a .gz file.

3. Final Answer:

   file.txt is not a compressed .gz file -> Option B

4. Quick Check:

   gunzip needs .gz files [OK]

Hint: gunzip only works on gzip-compressed (.gz) files [OK]

Common Mistakes:

• Trying to decompress uncompressed files
• Confusing gzip and gunzip commands
• Ignoring file extensions

5. You have multiple log files: log1.txt, log2.txt, and log3.txt. You want to compress all of them but keep the original files. Which command will do this correctly?

hard

A. gzip -k log*.txt

B. gzip log*.txt

C. gunzip -k log*.txt

D. gzip -d log*.txt

Solution

1. Step 1: Identify command to compress multiple files

   gzip compresses files; log*.txt matches all log files.

2. Step 2: Ensure original files are kept

   The -k option keeps original files after compression.

3. Final Answer:

   gzip -k log*.txt -> Option A

4. Quick Check:

   gzip -k compresses and keeps originals [OK]

Hint: Use gzip -k with wildcard to keep originals [OK]

Common Mistakes:

• Using gunzip instead of gzip for compression
• Not using -k and losing original files
• Using -d which decompresses files