Installing Alternative PHP Cache (APC) on OSX.

`APC` is an opcode cache for optimizing PHP performance. Here is the steps to install it on Mac.

1. Create a src directory [Optional].
*$ cd /usr/local/
$ mkdir src
$ cd src* 2. Download `PCRE`, the `APC` requires `PCRE` libraries and header files.

$ curl -O ftp://ftp.csx.cam.ac.uk//pub/software/programming/pcre/pcre-8.31.tar.gz

3. Unzip the downloaded file.

$ tar -xvzf pcre-8.31.tar.gz

4.Install `PCRE`.
*$ cd pcre-8.31
$ ./configure
$ make
$ sudo make install* 5. Install `APC`.

$ sudo pecl install apc

6. Put the following line into the end of `php.ini` file.

$ extension=apc.so

7. Make sure that you have completely install `APC`.

$ php -m | grep apc  #should return "apc"