让history 命令显示时间

echo ‘HISTTIMEFORMAT=”%F %T “‘ >> /etc/profile
source /etc/profile

增加虚拟内存

dd if=/dev/zero of=/var/swap bs=1024 count=4096000
mkswap /var/swap
mkswap -f /var/swap
swapon /var/swap

删除虚拟内存

swapoff /var/swap
rm -rf /var/swap

linux上传和下载文件

yum install lrzsz

  1. rz 上传
  2. sz 文件路径 下载路径

    jdk

    yum -y install java-1.8.0-openjdk java-1.8.0-openjdk-devel
    echo ‘
    #set java environment
    export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk
    export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
    export PATH=$PATH:$JAVA_HOME/bin
    ‘ >> /etc/profile
    source /etc/profile
    java -version