command record

env lists all environment variables
set lists all variables
tar zcppf / save path / file path
less view paging
netstat list all tcp connection information

install tools
yum groupinstall "Base" -y
yum groupinstall "Development tools" -y
yum groupinstall "Compatibility libraries" -y
yum groupinstall "Debugging tools" -y


delete linux's own jdk
rpm -qa | grep jdk
java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.i686
java-1.6.0- openjdk-1.6.0.0-1.66.1.13.0.el6.i686

rpm -qa | grep gcj
libgcj-4.4.7-4.el6.i686

rpm -e --nodeps java-1.7.0-openjdk-1.7.0.45- 2.4.3.3.el6.i686



compile
make PREFIX=/application/hadoop/cache/redis install