Скачать или смотреть Efficiently Generate Formatted CSV Output from Linux find Command

Learn how to quickly generate a structured CSV file from the output of the `find` command in Linux, reducing processing time and improving efficiency.
---
This video is based on the question https://stackoverflow.com/q/64125084/ asked by the user 'Linuxfluesterer' ( https://stackoverflow.com/u/14349790/ ) and on the answer https://stackoverflow.com/a/64125874/ provided by the user 'tink' ( https://stackoverflow.com/u/1394729/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Linux: fast creating of formatted output file (csv) from find command

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Efficiently Generate Formatted CSV Output from Linux find Command

When working in Linux, particularly with large sets of files across multiple devices, you might find yourself needing to format file output for easier management and database entry. One common use case is preparing a CSV (Comma-Separated Values) file from the list of files generated by the find command. However, if you have attempted this, you might have encountered performance issues that make the task cumbersome and time-consuming. In this guide, we will explore how to create a properly formatted CSV output file efficiently, bypassing common pitfalls with slow processing methods.

Problem Overview

In your scenario, you were tasked with generating a CSV file listing various files located in /mnt/sda4, while ensuring that certain entries, specifically those containing .cache, were omitted from the list. You initially began with the following commands:

[[See Video to Reveal this Text or Code Snippet]]

This command successfully stripped the path, resulting in a file list that was generated quickly, taking just over a second.

However, your attempts to format this output into a useful CSV for database input fell flat, taking excessive amounts of time:

[[See Video to Reveal this Text or Code Snippet]]

This method took nearly 28 minutes! Clearly, further optimization was necessary.

A Faster Solution Using awk

The root cause of the performance slowdown stems from the looping and multiple redirection operations. A more efficient approach leverages the power of awk, a programming language ideal for pattern scanning and processing. Here's how you can use it:

Step-by-Step Solution

Combining Operations: Instead of creating intermediate files and processing them line by line, you can use awk to handle the formatting inline with the find command.

Use the Following Command:

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Command

time find /mnt/sda4/: Start by finding all files in the specified directory.

awk '...': This part processes the output of the find command. Here’s what’s happening inside the awk script:

BEGIN{FS=OFS="/"}: Sets the input and output field separators to /. This allows us to easily manipulate the file paths.

!/.cache/: This filter omits any files that contain .cache.

{$2=$3="";}: This clears out the unnecessary levels of the file path.

new=sprintf("%s",$0);: Formats the current file path without the cleared parts.

gsub(/^////,"",new);: Cleans up the path by removing unwanted slashes.

printf "06;%s;/%s\n",$NF,new: Outputs the desired format, combining the basename and the cleaned path into a CSV line.

Expected Results

Using this streamlined command, you'll achieve significantly faster execution times, warranting a more responsive data processing experience. Rather than waiting nearly half an hour, you can expect results in just a few seconds.

Conclusion

Efficiently generating formatted output from complex file systems in Linux can be daunting. With the right command structure—utilizing awk alongside find—you can create a clean, structured CSV output that is both fast and effective. Armed with this knowledge, you'll be better prepared to manage your data and handle database imports seamlessly.

Now, it's time to streamline your file management tasks with this improved approach!