I have this very large dictionary file with 1 word on each line, and I would like to trim it down.

What I would like to do is leave 3-6 letter improper nouns, so it has to detect the words based on these:

1. if the word is less than 3 letters, delete it
2. if the word is more than 6 letters, delete it
3. if the word has a capital letter, delete it
4. if the word has a single quote or space, delete it.

I used this:

```
cat Downloads/en-US/en-US.dic | egrep '[a-z]{3,6}' > Downloads/3-6.txt

```

but the output is incorrect. It outputs the words with greater than 3 characters alright, but that's about my progress so far.

So how do I go about doing this in the mac terminal? There must be a way to do this right?