erwin@erwin-M720SRS:~$ sudo apt-get install php-pear php5-dev make libpcre3-dev
[sudo] password for erwin:
Reading package lists... Done
Building dependency tree
Reading state information... Done
libpcre3-dev is already the newest version.
make is already the newest version.
php-pear is already the newest version.
php5-dev is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
erwin@erwin-M720SRS:~$ sudo pecl install apc
WARNING: channel "pecl.php.net" has updated its protocols, use "pecl channel-update pecl.php.net" to update
downloading APC-3.1.13.tgz ...
Starting to download APC-3.1.13.tgz (171,591 bytes)
.....................................done: 171,591 bytes
could not extract the package.xml file from "/build/buildd/php5-5.5.9+dfsg/pear-build-download/APC-3.1.13.tgz"
Download of "pecl/apc" succeeded, but it is not a valid package archive
Error: cannot download "pecl/APC"
Download failed
install failed
erwin@erwin-M720SRS:~$ apt-cache search php-apc
php-apc - APC User Cache for PHP 5 (transitional package)
php5-apcu - APC User Cache for PHP 5
erwin@erwin-M720SRS:~$ php -v
PHP 5.5.9-1ubuntu4.7 (cli) (built: Mar 16 2015 20:48:03)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
    with Zend OPcache v7.0.3, Copyright (c) 1999-2014, by Zend Technologies
erwin@erwin-M720SRS:~$ ^C
erwin@erwin-M720SRS:~$