centos6.4安装iftop
yum install gcc
yum -y install libpcap libpcap-devel
yum -y install ncurses ncurses-devel
htop：
wget http://nchc.dl.sourceforge.net/project/htop/htop/1.0.1/htop-1.0.1.tar.gz
tar zxvf htop-1.0.1.tar.gz
cd htop-1.0.1
./configure
make
make install
原文：http://www.cnblogs.com/leocook/p/linux_centos_tops.html