Sorry if the question is a bit out of place but I've just started learning Linux 2 days and I don't really have any knowledge to get around the problem myself.
I was trying out the `grep` command using this fruit list [here](https://media.geeksforgeeks.org/wp-content/cdn-uploads/20210701185945/Fruits-name-by-amnindersingh_141414.txt) and everything was going fine until I went on to try the `/` expression.

I think I pressed some kind of key combination with the underscore and now most regular expressions seem to be messed up (as well as the file name is now underlined, if that's important in any way). For example when I type:

```
cat fruits | grep ^ma

```

I get no results, `mandarine` and `mango` don't show up.

When I type:

```
cat fruits | grep dam*

```

or

```
cat fruits | grep dam

```

`Damson` doesn't show up. On top of that there is an error cross on the right side of the terminal:

[![enter image description here](https://i.stack.imgur.com/YTq70.png)](https://i.stack.imgur.com/YTq70.png)

Could anyone explain in simple terms how to get it working again? Thanks a lot!