Скачать или смотреть Batch Conversion of Columns into Rows with File Name: A Step-by-Step Guide

Learn how to efficiently convert columns into rows across multiple files using GNU awk, while retaining file names and organizing data seamlessly.
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Batch Conversion of Columns into Rows with File Name: A Step-by-Step Guide

When managing large datasets, especially those spread across numerous files, the ability to consolidate information is crucial. If you've ever faced the challenge of transforming columns into rows while retaining original filenames, you know how daunting this task can be. This guide walks you through a simple solution using GNU awk, a powerful text-processing tool, to help you accomplish batch conversion efficiently.

The Problem

Suppose you have over 1000 tab-limited files that contain data in the following format:

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You want to convert these files into a single output format that looks like this:

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Many people may try to accomplish this using generic text processing commands, but they often struggle with retaining both the structure and the filenames. Let's explore the solution using awk.

The Solution Using GNU Awk

To achieve the desired output format, we can leverage GNU awk's powerful text manipulation capabilities. Below is a step-by-step breakdown of how to implement this:

Step 1: Prepare Awk Script

Create a new file named tst.awk with the following content:

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Explanation of the Script

BEGIN Block: Sets the input and output field separator to a tab (\t).

Main Block: For each line in the input files:

Loops through each field (column) and constructs an associative array a[i] that concatenates the values, separated by commas.

ENDFILE Block: When finishing processing a file, it prints the filename, followed by the concatenated values for each field.

Step 2: Run the Script

After saving the script, execute it in your terminal with multiple files as follows:

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You will notice an output resembling:

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Alternative Method

For scenarios where you need to initiate a print operation upon reading the first record from each file, you can modify your tst.awk script as follows:

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Final Thoughts

Using GNU awk, you can efficiently consolidate data spread across multiple files into a structured format that includes the original filenames. This method is powerful and scalable for handling large datasets, making it easier to analyze and process further.

By following this guide, you can tackle the common problem of batch data conversion with ease and clarity. This skill is invaluable for anyone working with large datasets, ensuring you can always manage and transform your data seamlessly.