查看u盘 diskutil list 解挂u盘 diskutil unmountDisk /dev/disk3 写系统到u盘 sudo dd if=/Users/chenqi/Downloads/CentOS-7-x86_64-DVD-2009.iso of=/dev/rdisk3 bs=32m

下载JDK Java SE 8的官方网址 jdk下载路径 点击下载 解压文件 tar -xvf jdk-8u65-linux-x64.tar.gz 添加环境变量 echo " ">>/etc/profile echo "# Made for java env by chenqi on $(date +%F)">>/etc/profile echo 'export JAVA_HOME=/usr/local/java'>>/etc/profile echo 'export JRE_HOME=${JAVA_HOME}/jre'>>/etc/profile echo 'export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib'>>/etc/profile echo 'export PATH=${JAVA_HOME}/bin:$PATH'>>/etc/profile tail -4 /etc/profile source /etc/profile echo $PATH 环境变量 ...