How to use patterns in a case statement?

Brace expansion doesn’t work, but *, ? and [] do. If you set shopt -s extglob then you can also use extended pattern matching:

• ?() – zero or one occurrences of pattern
• *() – zero or more occurrences of pattern
• +() – one or more occurrences of pattern
• @() – one occurrence of pattern
• !() – anything except the pattern

Here’s an example:

shopt -s extglob
for arg in apple be cd meet o mississippi
do
    # call functions based on arguments
    case "$arg" in
        a*             ) foo;;    # matches anything starting with "a"
        b?             ) bar;;    # matches any two-character string starting with "b"
        c[de]          ) baz;;    # matches "cd" or "ce"
        me?(e)t        ) qux;;    # matches "met" or "meet"
        @(a|e|i|o|u)   ) fuzz;;   # matches one vowel
        m+(iss)?(ippi) ) fizz;;   # matches "miss" or "mississippi" or others
        *              ) bazinga;; # catchall, matches anything not matched above
    esac
done