I was given this as a solution to a problem of needing to remove blank lines from a file.
cat create_user.sql | egrep -i '[a-z0-9\-]'
The way i'm understanding i should get everything a thru z and 0 thru 9 plus the underscore _.
I got all this plus quotes double and single ' " and semicolon ; all of which is fine. I just don't understand how i got these characters in addition to the ones in the regular expression.