regex - Regular expressions in a Bash case statement

Question

I am using following script, which uses case statement to find the server.

    #!/bin/bash
SERVER=$1;
echo $SERVER | egrep "ws-[0-9]+.host.com";
case $SERVER in
ws-[0-9]+.host.com) echo "Web Server"
;;
db-[0-9]+.host.com) echo "DB server"
;;
bk-[0-9]+.host.com) echo "Backup server"
;;
*)echo "Unknown server"
;;
esac

But it is not working. Regex is working with egrep but not with case. sample O/P

./test-back.sh ws-23.host.com
ws-23.host.com
Unknown server

Any Idea ?

Answer 1

Bash case does not use regular expressions, but shell pattern matching only.

Therefore, instead of regex ws-[0-9]+.host.com you should use pattern ws*.host.com (or ws-+([0-9]).host.com, but that looks a bit advanced and I've never tried that :-)