Download the SQL Anywhere PHP extension source code from  http://www.sybase.com/detail?id=1019698. Look for the section entitled Building the Driver from Source.

From the directory where you saved the SQL Anywhere PHP extension, extract the files to the ext subdirectory of the PHP source tree (Mac OS X users should replace tar with gnutar):

$ tar -xzf sasql_php.zip -C PHP-source-directory/ext/

For example:

$ tar -xzf sqlanywhere_php-1.0.8.tar.gz -C ~/php-5.2.11/ext

Make PHP aware of the extension:

$ cd PHP-source-directory/ext/sqlanywhere
$ touch *
$ cd ~/PHP-source-directory
$ ./buildconf

The following example is for PHP version 5.2.11. You must change php-5.2.11 below to the version of PHP you are using.

$ cd ~/php-5.2.11/ext/sqlanywhere
$ touch *
$ cd ~/php-5.2.11
$ ./buildconf

Verify that PHP is aware of the extension:

$ ./configure -help | egrep sqlanywhere

If you were successful in making PHP aware of the SQL Anywhere extension, you should see the following text:

--with-sqlanywhere=[DIR]

If you are unsuccessful, keep track of the output of this command and post it to the SQL Anywhere Forum at  http://sqlanywhere-forum.sybase.com/ for assistance.