安装步骤:
1.更新下载通道:
pear channel-update pear.php.net
关键字: pear
需要的pear包可以到官网下载安装http://pear.php.net/packages.php
例如：
/usr/local/bin/pear install –alldeps http://download.pear.php.net/package/HTTP_Request-1.4.2.tgz
/usr/local/bin/pear install –alldeps http://download.pear.php.net/package/Log-1.10.1.tgz