Question

I’m looking to match a file extension pattern in a Bash case statement.

So far I have tried /(\.).{3}/:

case ${myArray[count]} in

 *CODE*) $codeFound[count]=${myArray[count]};;
/(\.).{3}/) $extensionFound[count]=${myArray[count]};;

esac

The pattern match for CODE works, however I am having trouble with the pattern for file extensions.
The above throws an error:

syntax error near unexpected token `(‘

If I wrap the RegEx in @() e.g. @(/(\.).{3}/) the pattern isn’t matched either.

Thanks

Answer 1

The pattern matching in a case statement does not use regular expression. From the manpage:

A case command first expands word, and tries to match it against
each pattern in turn, using the same matching rules as for path‐
name expansion (see Pathname Expansion below).

You will either need to use a block of if statements, or do further regex checking based on a loose glob in the case statement.

case ${myArray[count]} in

 *CODE*) 
     $codeFound[count]=${myArray[count]};;
 *.*) 
   if [[ ${myArray[count]} =~ \..{3} ]]; then 
      $extensionFound[count]=${myArray[count]}
   fi;;

esac