How to Format a Text File in Shell Script: A Simple Guide to Remove Lines, Spaces, and Format Output

Learn how to efficiently format a text file in shell script by removing lines, spaces, and formatting output with quotes and commas.
---

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: Remove first two lines, last two lines and space from file and add quotes on each line and replace newline with commas in shell script

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Format a Text File in Shell Script: A Simple Guide to Remove Lines, Spaces, and Format Output

The Problem

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

Remove the first two lines and last two lines.

Eliminate all spaces at the start and end of each line.

Enclose each line within single quotes (' ').

Replace newlines with commas.

This means the final output should look like:

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

The Solution

Here’s a shell script command that will accomplish the task. Although it's not a one-liner, it effectively formats the file according to the specifications provided:

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

Now, let's break it down into manageable parts to understand how it works.

Understanding the Command

The command consists of two distinct sed operations. Each part performs specific tasks:

Initial Transformations:

s/^ */'/: This part adds a starting single quote to the beginning of each line after removing spaces.

s/$/',/: This adds a comma and a closing single quote at the end of each line.

1,2d: This removes the first two lines of the input file.

N; $!P;$!D;$d: This reads the next line and prepares to manipulate it. It effectively deletes the last two lines of text.

Merging Lines:

H;1h;$!d;x: This sequence loads the entire content into the hold space, allowing us to manage it more effectively.

s/\n//g: This removes all newline characters (which separate lines).

s/,$//: Finally, this removes the trailing comma that would appear at the end of the output.

Implementing the Command

To implement this command, follow these steps:

Open your terminal.

Execute the sed command above.

Conclusion

So the next time you need to format a text file, remember this approach—it can save you time and make your data handling much more efficient!