How to Split and Rejoin Files Using Terminal Commands in Ubuntu

This is an article about the process of splitting large files into smaller pieces using shell commands on Ubuntu, and then rejoining them back together seamlessly. In this article you will find information about how to use the split command for dividing files into manageable chunks and the cat, dd, or similar tools for merging these files back into their original form.

Introduction

Working with large files can be challenging on any operating system, but Ubuntu’s robust terminal-based file management commands offer a powerful solution. The process of splitting files into smaller segments not only makes them easier to handle but also facilitates backup and transfer operations over networks that have limitations in terms of data size or speed. Furthermore, understanding how to reassemble these pieces once they’ve been split is crucial for maintaining the integrity and usability of your data.

In this article, you will learn about the split command and other utilities available within Ubuntu’s terminal interface for file splitting, as well as methods to seamlessly merge them back together. The focus here will be on shell scripting techniques that can automate these tasks efficiently.

Prerequisites

Before diving into the specifics of file splitting and rejoining, ensure your system meets a few basic requirements:

1. Ubuntu Installation: Your computer should have Ubuntu installed.
2. Terminal Access: You must know how to access and use the terminal window.
3. Basic Command Line Knowledge: Familiarity with basic shell commands is necessary.

Understanding File Splitting

The split Command

The split command allows you to break down files into smaller, more manageable pieces based on certain criteria such as file size or number of lines. This utility comes pre-installed in most Linux distributions including Ubuntu and can be used effectively for various purposes like backup, transfer over limited bandwidth connections, etc.

Syntax of the Split Command

The basic syntax for using split is:

• Options:
  • -b <size>: Splits file into pieces with a specified size (e.g., -b 10M splits files into 10MB chunks).
  • -l <lines>: Splits based on the number of lines instead of bytes.
  • --verbose: Outputs information about what is being split.

Examples

Let’s look at some practical examples to understand how these options work:

This command will create multiple files starting with “smallfiles_” each containing up to 5MB of data from largefile.txt.

Another useful example might be splitting by number of lines:

Here, the input file is divided such that each chunk has at most 100 lines.

Splitting Files for FTP Transfer

When dealing with large files destined for an FTP server, it’s often necessary to split them into smaller parts so they can be uploaded efficiently. For instance:

This splits a 10GB zip archive named hugefile.zip into chunks of approximately 2GB each.

Merging Files Back Together

After transferring or working with individual pieces, the next step is reassembling them back to their original state. This process involves using the cat command to concatenate these files in the correct order.

Using Cat Command for Reassembly

The cat command concatenates (joins together) file contents and sends it to standard output (usually your terminal). It’s a versatile tool that can also be used to merge split files back into one:

This merges all the smaller files created from splitting an original text file named originalfile.txt and writes them back together.

Advanced Techniques

For more complex scenarios, consider these advanced tips:

• Preserve File Order: Ensure you keep track of how files are split; use consistent naming conventions if splitting manually.
• Automate with Shell Scripts: Use shell scripts to automate both the splitting and merging processes for repetitive tasks or large datasets.

Example Script for Automating Splitting and Rejoining

Below is a simple bash script example demonstrating automation:

This script splits a large file into smaller parts and provides an easy way to merge them back together automatically.

Conclusion

Mastering the art of splitting files using shell commands in Ubuntu is invaluable for managing large datasets efficiently. By leveraging tools like split and cat, you can handle big files with ease, making backups, transfers, or even archiving more straightforward. Additionally, incorporating these methods into custom scripts adds a layer of automation to routine tasks, enhancing productivity significantly.

Read this article to find out about the comprehensive steps involved in splitting large files and reassembling them using shell commands in Ubuntu’s terminal interface. With practice and experimentation, you’ll soon be adept at manipulating file sizes to suit your computing needs effortlessly.