regex for one character or another?

Question

I'm searching for a regex code which lists all the lines that contain an a OR an i. I tryed this:

grep -E '[(a|i)]{1}' testFile.txt

but this gives me the words containing a or i and words that contain a en i. What's wrong?

Answer 1

You can achieve that with:

grep -E "^[^ai]*(a|i){1}[^ai]*$" testFile.txt