How to Extract Specific File Types from 7-Zip Archives with Bash

Learn how to extract specific file types from 7-Zip archives with bash, while preserving the original folder structure. This article explains the problem and the solution, with examples and references.

7-Zip is a popular file archiver that can compress and decompress various file formats, such as 7z, zip, tar, gzip, and more. Sometimes, you may want to extract only certain file types from a 7-Zip archive, such as images, documents, or audio files. However, using the standard 7-Zip commands may not give you the desired result, as they may extract all the files or lose the original folder structure. In this article, we will show you how to extract specific file types from 7-Zip archives with bash, while keeping the original folder structure intact. We will also provide some examples and references for further reading.

Problem: Extracting Specific File Types from 7-Zip Archives

Suppose you have a 7-Zip archive that contains several files and folders, such as:

• archive.7z
  • folder1
    • file1.txt
    • file2.jpg
    • file3.pdf
  • folder2
    • file4.png
    • file5.docx
    • file6.mp3

Now, you want to extract only the image files (jpg and png) from this archive, and save them in a separate folder, such as:

• images
  • folder1
    • file2.jpg
  • folder2
    • file4.png

However, if you use the standard 7-Zip command to extract the archive, such as:

7z x archive.7z -oimages

You will get all the files extracted, not just the image files. Moreover, the folder structure will be flattened, and you will end up with something like:

• images
  • file1.txt
  • file2.jpg
  • file3.pdf
  • file4.png
  • file5.docx
  • file6.mp3

This is not what you want. You want to extract only the image files, and preserve the original folder structure. How can you do that?

Solution: Using Bash to Extract Specific File Types from 7-Zip Archives

One possible solution is to use bash, a command-line interpreter that can run commands and scripts on Linux and other Unix-like systems. Bash can also run on Windows, if you have a compatible environment, such as Cygwin or WSL.

With bash, you can use a combination of commands and loops to extract specific file types from 7-Zip archives, while keeping the original folder structure. Here is a general outline of the steps:

1. Create a temporary folder to extract the entire archive.
2. Use the 7z x command to extract the archive to the temporary folder.
3. Create a target folder to store the extracted files of the desired type.
4. Use the find command to search for the files of the desired type in the temporary folder.
5. Use the cp –parents command to copy the files of the desired type to the target folder, while preserving the original folder structure.
6. Use the rm -r command to delete the temporary folder.

Here is an example of a bash script that implements these steps, assuming that the archive name is archive.7z and the desired file type is jpg:

#!/bin/bash

# Create a temporary folder
tmpdir=$(mktemp -d)

# Extract the archive to the temporary folder
7z x archive.7z -o$tmpdir

# Create a target folder
mkdir images

# Find and copy the jpg files to the target folder, while preserving the folder structure
find $tmpdir -type f -name "*.jpg" -exec cp --parents {} images \;

# Delete the temporary folder
rm -r $tmpdir

You can save this script as a file, such as extract.sh, and run it with the command:

bash extract.sh

This will create a folder named images that contains only the jpg files from the archive, with the original folder structure. For example:

• images
  • folder1
    • file2.jpg
  • folder2
    • file4.png

You can modify the script to suit your needs, such as changing the archive name, the file type, or the target folder name. You can also use multiple file types by using the -o option of the find command, such as:

find $tmpdir -type f \( -name "*.jpg" -o -name "*.png" \) -exec cp --parents {} images \;

This will find and copy both jpg and png files to the target folder.

Frequently Asked Questions (FAQs)

Question: What is 7-Zip?

Answer: 7-Zip is a free and open-source file archiver that can compress and decompress various file formats, such as 7z, zip, tar, gzip, and more. You can download 7-Zip from its official website.

Question: What is bash?

Answer: Bash is a command-line interpreter that can run commands and scripts on Linux and other Unix-like systems. Bash can also run on Windows, if you have a compatible environment, such as Cygwin or WSL.

Question: How can I run bash on Windows?

Answer: You can run bash on Windows by installing a compatible environment, such as Cygwin or WSL. Cygwin is a software package that provides a Unix-like environment and tools on Windows. WSL is a feature that allows you to run Linux distributions natively on Windows 10 and Windows 11.

Question: How can I learn more about 7-Zip commands and options?

Answer: You can learn more about 7-Zip commands and options by reading its documentation or by using the 7z –help command.

Question: How can I learn more about bash commands and syntax?

Answer: You can learn more about bash commands and syntax by reading its manual or by using the man bash command.

Summary

In this article, we have shown you how to extract specific file types from 7-Zip archives with bash, while preserving the original folder structure. We have explained the problem and the solution, with examples and references. We hope you have found this article useful and informative. If you have any questions or feedback, please feel free to leave a comment below.

Disclaimer: This article is for educational purposes only and does not constitute professional advice. The author and the publisher are not responsible for any damages or losses that may result from the use of the information or the code in this article. Use at your own risk.