regular expression
A pattern used to match variable text. The elements of a regular expression
include: literal characters that must match exactly; the wildcard symbols--* to
mean one or more characters here and ? to mean any one character; and the
class--a list of characters (within brackets) that are acceptable. The MATCHES and
LIKE operators of SQL allow you to search for character strings that match to
regular expression patterns.
See also expression, literal, wildcard.