How to use patterns in a case statement?

Question

The man page says that case statements use "filename expansion pattern matching".
I usually want to have short names for some parameters, so I go:

case $1 in     req|reqs|requirements) TASK="Functional Requirements";;     met|meet|meetings) TASK="Meetings with the client";; esac  logTimeSpentIn "$TASK" 

I tried patterns like req* or me{e,}t which I understand would expand correctly to match those values in the context of filename expansion, but it doesn't work.

Answer 1

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 

Answer 2

I don't think you can use braces.

According to the Bash manual about case in Conditional Constructs.

Each pattern undergoes tilde expansion, parameter expansion, command substitution, and arithmetic expansion.

Nothing about Brace Expansion unfortunately.

So you'd have to do something like this:

case $1 in     req*)         ...         ;;     met*|meet*)         ...         ;;     *)         # You should have a default one too. esac