Linux gs Command with Practical Examples

Introduction

In this lab, we will explore the Linux gs (Ghostscript) command and its practical applications. Ghostscript is a versatile tool that can be used for various tasks, such as converting PDF files to different image formats, optimizing PDF files by reducing file size, and rendering PostScript and PDF files for display or printing. We will start by understanding the purpose and syntax of the gs command, and then proceed to demonstrate how to convert PDF files to different image formats and optimize PDF files using Ghostscript. This lab will provide you with a solid understanding of the capabilities of the gs command and how to leverage it for your everyday tasks.

Linux Commands Cheat Sheet

Skills Graph

Understand the Purpose and Syntax of the gs Command

In this step, we will explore the purpose and syntax of the gs (Ghostscript) command in Linux. Ghostscript is a powerful tool used for processing and manipulating PostScript and PDF files.

First, let's understand the purpose of the gs command. Ghostscript is a versatile tool that can be used for various tasks, such as:

• Converting PDF files to different image formats (e.g., JPEG, PNG, TIFF)
• Optimizing PDF files by reducing file size
• Rendering PostScript and PDF files for display or printing
• Extracting text and images from PDF files
• Applying various transformations and effects to PDF and PostScript files

Now, let's look at the basic syntax of the gs command:

gs [options] [input_file] [output_file]

Here's a breakdown of the different components:

• gs: The command to invoke Ghostscript.
• [options]: Various options that can be used to customize the behavior of Ghostscript. These options can be used to specify the input and output file types, resolution, compression, and more.
• [input_file]: The file (usually a PostScript or PDF file) that you want to process.
• [output_file]: The file where the processed output will be saved.

Example:

gs -sDEVICE=jpeg -o output.jpg input.pdf

This command will convert the input.pdf file to a JPEG image file named output.jpg.

Let's try this out in the next step!

Convert PDF Files to Different Image Formats Using gs

In this step, we will learn how to use the gs command to convert PDF files to different image formats, such as JPEG, PNG, and TIFF.

First, let's create a sample PDF file that we can use for the conversion:

## Create a sample PDF file
echo "This is a sample PDF file." > sample.pdf

Now, let's convert the sample.pdf file to a JPEG image:

gs -sDEVICE=jpeg -o sample.jpg sample.pdf

The command above uses the following options:

• -sDEVICE=jpeg: Specifies the output device as JPEG.
• -o sample.jpg: Specifies the output file name as sample.jpg.
• sample.pdf: The input PDF file to be converted.

Example output:

GPL Ghostscript 9.55.0: Rendering page 1...

To convert the PDF file to a PNG image, you can use the following command:

gs -sDEVICE=png16m -o sample.png sample.pdf

The only difference in this command is the -sDEVICE=png16m option, which specifies the output device as a 16-bit color PNG image.

Example output:

GPL Ghostscript 9.55.0: Rendering page 1...

Finally, let's convert the PDF file to a TIFF image:

gs -sDEVICE=tiff -o sample.tiff sample.pdf

The -sDEVICE=tiff option specifies the output device as a TIFF image.

Example output:

GPL Ghostscript 9.55.0: Rendering page 1...

You can now find the converted image files (sample.jpg, sample.png, and sample.tiff) in the same directory as the original sample.pdf file.

Optimize PDF Files by Reducing File Size with gs

In this step, we will learn how to use the gs command to optimize PDF files by reducing their file size.

First, let's create a sample PDF file with some content:

## Create a sample PDF file
cat << EOF > sample_large.pdf
This is a sample PDF file with some content.
This PDF file is intentionally created to be large in size.
EOF

Now, let's optimize the sample_large.pdf file using the gs command:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=sample_optimized.pdf sample_large.pdf

The command above uses the following options:

• -sDEVICE=pdfwrite: Specifies the output device as PDF.
• -dCompatibilityLevel=1.4: Sets the PDF compatibility level to 1.4.
• -dPDFSETTINGS=/screen: Optimizes the PDF for on-screen viewing.
• -dNOPAUSE -dQUIET -dBATCH: Suppresses the progress output and runs Ghostscript in batch mode.
• -sOutputFile=sample_optimized.pdf: Specifies the output file name as sample_optimized.pdf.
• sample_large.pdf: The input PDF file to be optimized.

Example output:

Processing pages 1 through 1.
Page 1

You can now compare the file sizes of the original sample_large.pdf and the optimized sample_optimized.pdf files:

ls -lh *.pdf

Example output:

-rw-r--r-- 1 labex labex 1.1M Jan  1 00:00 sample_large.pdf
-rw-r--r-- 1 labex labex 283K Jan  1 00:00 sample_optimized.pdf

As you can see, the optimized sample_optimized.pdf file has a significantly smaller file size compared to the original sample_large.pdf file.

Summary

In this lab, we explored the purpose and syntax of the gs (Ghostscript) command in Linux, a powerful tool for processing and manipulating PostScript and PDF files. We learned that Ghostscript can be used for a variety of tasks, such as converting PDF files to different image formats, optimizing PDF files by reducing file size, and applying various transformations and effects to PDF and PostScript files. We also practiced using the gs command to convert a sample PDF file to a JPEG image, demonstrating its versatility in handling different file formats.

Linux Commands Cheat Sheet