[FAQ] What's the difference between i and t in docker run -it?

[elcapo]

Course

data-engineering-zoomcamp

Question

What's the difference between i and t in docker run -it?

Answer

When running containers interactively, Docker provides two commonly used flags: -i (interactive) and -t (tty). They are often used together as -it, but they serve different purposes.

• -i keeps the container’s STDIN open, even if it is not attached to a terminal. This allows you send input to the process running inside the container.

echo "print(2+2)" | docker run -i python

• -t allocates a pseudo-terminal (TTY) for the container. This provides proper terminal formatting (line breaks, colors, prompts).

docker run -t ubuntu date

Using both flags together gives you 1) an open input stream and 2) a real terminal interface. This is what you normally want for an interactive shell session.

docker run -it ubuntu bash

Checklist

• I have searched existing FAQs and this question is not already answered
• The answer provides accurate, helpful information
• I have included any relevant code examples or links

[github-actions]

✅ FAQ NEW proposal created in PR #108

Please review and approve the changes.