因为我想使用nginx，我不想安装apache2
http://packages.ubuntu.com/lucid-updates/php5-curl在这个链接中，没有对apache2的依赖。
root@ubuntu:/etc/apt/apt.conf.d# apt-get install --no-install-recommends php5-curl
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
apache2-mpm-prefork apache2-utils apache2.2-bin apache2.2-common libapache2-mod-php5 libaprutil1-dbd-sqlite3
libaprutil1-ldap
Suggested packages:
apache2-doc apache2-suexec apache2-suexec-custom php-pear
Recommended packages:
ssl-cert
The following NEW packages will be installed:
apache2-mpm-prefork apache2-utils apache2.2-bin apache2.2-common libapache2-mod-php5 libaprutil1-dbd-sqlite3
libaprutil1-ldap php5-curl
0 upgraded, 8 newly installed, 0 to remove and 49 not upgraded.
Need to get 6,281kB of archives.
After this operation, 19.3MB of additional disk space will be used.
这是恼人的，我不能摆脱安装apache2
从链接中可以看到，该包依赖于phpapi-20090626，它是由libapache2-mod-php5、libapache2-mod-php5filter、php5-cgi或php5-cli中的一个提供的虚拟包。在没有理由不这样做的情况下，它将选择第一个，这取决于Apache。
要解决这个问题，手动安装提供phpapi-20090626的其他软件包之一。后两个选项不依赖于Apache。
apt-get install php5-cli
apt-get install php5-curl