wildcard_meaning

* Matches any characters
? Matches any single character
[characters] Matches any character that is a member of the set characters
[!characters] Matches any character that is not a member of the set characters
[[:class:]] Matches any character that is a member of the specified

class

[:alnum:] Matches any alphanumeric character
[:alpha:] Matches any alphabetic character
[:digit:] Matches any numeral
[:lower:] Matches any lowercase letter
[:upper:] Matches any uppercase letter