Question

I am using Bash (cygwin), and I would like to implement something like a progress indicator that spans vertical lines. It replaces the console output and does not append to it. It needs to look like an animation.

So this output appears over time:

Iteration 1:

---
---
---

Iteration 2:

*--
---
---

Iteration 5:

***
*--
---

The trick is to span vertical lines.

It is easy with echo if you do not span vertical lines. I can use \b to move backwards a space and overwrite previous characters:

echo -n -e "\b"

But how do you move up a line and overwrite previous lines.

Answer 1

You use ANSI escape-sequence to move the cursor:

\033[NA   - cursor up N lines
\033[NB   - cursor down N lines
\033[NC   - cursor right N steps
\033[ND   - cursor left N steps

so

$ echo -e '\033[8Chello'
        hello