You’ve likely heard you should never run a command or script that you don’t fully understand in the Linux terminal (or any command line). Unfortunately, the syntax for command-line apps can be tricky to break down and understand. Here’s how ChatGPT can help.

Why Not All Terminal Commands Are Safe

The command line is a powerful tool, but it does not ask for permission. When you tell it to delete a file, it deletes it: there’s no confirmation, no recycle bin—the file is just gone, immediately. It also provides access to a lot of powerful tools for system administration and automation that can be abused. Internet tricksters are well known for responding to requests for advice with commands that look innocent but, when run, can cause havoc by wiping your hard drive, installing malware, or otherwise damaging your computer or data.

It’s also easy for a simple typo, or a script that was designed for a different system to have unintended effects when you run them. So, it pays to know what a helpful-looking Linux command or script that you’ve found online does before you run it.

How Do You Find Out What a Linux Command Does?

Figuring out what a command or script does usually means breaking down the syntax for the shell it is written for (usually Bash), and then reading the instructions for the programs that the script calls.

For example, you might need to figure out Bash conditional statements and variables, and read the man pages (built-in user manuals) for several commands before you can fully understand how a particular script works, and the impact it will have on your system. Usually, Linux gurus accumulate this knowledge over years, but there is a cheeky shortcut: ChatGPT.

Up front, you shouldn’t just paste a snippet of code into an AI chatbot and believe what it says about it: AI makes mistakes, and it makes them a lot more than people realize. However, it can give you a foothold in understanding a complex command, and help you break down the components so that you can look them up yourself to see what they do.

Example: Getting ChatGPT To Help Understand Complex Terminal Commands

Our article on converting image formats from the Linux command line includes a number of commands that use loops and different ImageMagick functions that are confusing at first glance. Here’s what happens when you ask ChatGPT to break it down:

Hey ChatGPT, can you please break this Linux command into its components and explain them?

for file in /path/to/source_directory/*.{jpg,jpeg,png}; do convert “$file” -gravity southeast -pointsize 20 -draw “text 5,5 ‘My Watermark'” “/path/to/output_directory/$(basename “$file”)”; done

Please include links to relevant man pages when possible.

And the result:

for file in /path/to/source_directory/*.{jpg,jpeg,png}

Iterates over all .jpg, .jpeg, and .png files in the source directory.

convert “$file”

Runs ImageMagick’s convert command to process the current file.

-gravity southeast

Positions the watermark at the bottom-right corner of the image.

-pointsize 20

Sets the font size of the watermark text to 20 points.

-draw “text 5,5 ‘My Watermark'”

Adds the text “My Watermark” at coordinates (5,5) relative to the bottom-right corner.

“/path/to/output_directory/$(basename “$file”)”

Saves the processed image in the output directory with the same filename.

What it Does:

For each image file in /path/to/source_directory/, the script:

• Adds a bottom-right watermark.
• Saves the modified image in /path/to/output_directory/.

Quick Links to Man Pages:

• Bash
  for
  loops
• ImageMagick
  convert
• ImageMagick Options:
  -gravity
  ,
  -pointsize
  ,
  -draw
• Bash
  basename

Not too shabby! And asking it to provide links to the man pages (again, those are the user manuals) also saves some web searches. That will let you learn more and verify the chatbot’s explanation.

While anyone with a bit of sense is cagey about the overuse of AI, this is one scenario where it can be really useful (writing Excel macros is another). Just remember: AI chatbots are useful tools, but they can be bamboozled by disreputable sources, or just plain make something up. They’re a convenient way to parse information, but always confirm their output.