How to install PHP xdiff extension on Debian?

Your goal is just to install the php diff extension. Just execute the following command.

cd /usr/src/
curl -O http://www.xmailserver.org/libxdiff-0.23.tar.gz
tar -xzf libxdiff-0.23.tar.gz 
cd libxdiff-0.23/
./configure
make
pecl install xdiff-2.0.1

Directly enter as prompted

libxdiff library installation dir? [autodetect] : /usr/src/libxdiff-0.23