Compress with bzip2

Gzip is not the only compression format you will meet. bzip2 uses a different encoding and commonly gives its output a .bz2 name. A bzip2 stream needs a tool that understands that format; changing its filename does not make it interchangeable with a gzip stream.

Let's repeat the report round trip with this tool. The useful skill is choosing the matching format and input/output behavior. Do not assume one compressor is always best: size, CPU time and compatibility depend on your data and the tools available to the receiver.

Prepare the example

Use a fresh directory with bzip2 installed. The first line writes the input report. We will preserve it while creating a compressed file, then read restored bytes through standard output so the compressed input remains available too.

Bash · Linux terminal

printf 'Diya: 72\n' > marks.txt
bzip2 -c marks.txt > marks.txt.bz2
bzip2 -dc marks.txt.bz2

Expected result

Diya: 72

bzip2 -c marks.txt encodes the report and writes the resulting stream to standard output. Redirection stores it in marks.txt.bz2. As in the gzip output-mode example, the source is not replaced by this operation.

bzip2 -dc marks.txt.bz2 uses the same format in the reverse direction: -d asks for decompression, while -c sends the restored content to output. The mark line should match the original. A gzip decompression command is not the right choice merely because this is also a compressed file; the format-specific tool must understand the bytes.

bzip2 is a file compressor that produces files ending in .bz2. Like gzip, it works on individual files and normally replaces the uncompressed source.

What is bzip2?

bzip2 is a command-line utility that compresses single files using the Burrows–Wheeler algorithm. It usually provides better compression ratios than gzip.

Step 1: Check if bzip2 is installed

On most modern Linux distros, bzip2 comes pre-installed. But you can verify it with this command:

bzip2 --version

If it's not installed, you can add it using your package manager:

sudo apt install bzip2      # Debian/Ubuntu
sudo yum install bzip2      # RHEL/CentOS
sudo dnf install bzip2      # Fedora

Step 2: Create a sample file

Let’s create a test file to practice with:

echo "This is a test file for compression." > testfile.txt

Step 3: Compress the file

Now let’s compress it using bzip2:

bzip2 testfile.txt

This command will replace the original file with a compressed version:

testfile.txt.bz2

Notice that the original testfile.txt is gone — it’s now inside the compressed file testfile.txt.bz2.

Want to Keep the Original File?

Use the -k (keep) option:

bzip2 -k testfile.txt

testfile.txt
testfile.txt.bz2

Step 4: View the compressed file size

ls -lh testfile.txt.bz2

Step 5: Decompress the file

To unzip it back to the original form, use bunzip2:

bunzip2 testfile.txt.bz2

Or use the -d flag with bzip2:

bzip2 -d testfile.txt.bz2

Compress Multiple Files?

bzip2 only works on single files. If you want to compress a whole folder or multiple files, you should first archive them using tar:

tar -cvjf archive.tar.bz2 foldername/

This tar command uses these options:

• -c: creates an archive
• -v: shows progress
• -j: compresses using bzip2
• -f: specifies the filename

Compress and restore files with bzip2

• bzip2 filename → compresses the file
• bunzip2 filename.bz2 → decompresses it
• -k option → keeps original file
• tar -cvjf → compresses directories

And that’s it! You now know how to compress and decompress files using bzip2. Keep practicing and try it on your own files.

Your task: Read a bzip2-compressed report without replacing it.

Use a fresh directory with bzip2 installed. The first line writes the input report. We will preserve it while creating a compressed file, then read restored bytes through standard output so the compressed input remains available too.

Bash · complete example for this question

printf 'Diya: 72\n' > marks.txt
bzip2 -c marks.txt > marks.txt.bz2
bzip2 -dc marks.txt.bz2

Expected result

Diya: 72

Worked answer

bzip2 -dc marks.txt.bz2

Use bzip2 -dc marks.txt.bz2 to read the restored report while keeping the compressed input. -c without decompression would encode the already-compressed stream again, which is not the restoration task. Choose the direction as well as the output destination.

Compression tools share some ideas, but their formats are not interchangeable. Match the decompressor to the data and make input preservation explicit. For a practical choice, compare compatibility and resource use on representative reports rather than relying on a universal claim about the best ratio.