I'm trying to compile freetds according to these instructions: http://www.mavrick.id.au/2012/php-5-3-6-mssql-freetds/

However configure is failing. My command is:

./configure --enable-msdblib -–prefix=/usr/local/freetds

I'm getting

configure: error: unrecognized option: `-–prefix=/usr/local/freetds'

Try `./configure --help' for more information.

for all command line options, even --help

I have build-essentials, gcc and make installed. I also tried sudo, even though I am logged in as root. It seems to me something is still missing?