centos

0. /sbin/ifconfig

1. mysql :

   *remove: yum -y remove mysql mysql-server
   *insatll: yum -y install mysql mysql-server
 
   *check: chkconfig --list | grep mysql
  
   *Set to Start on Boot:
       chkconfig mysqld on

   *start service:
       service --status-all
       service mysqld start
       check:  mysqladmin version    
 
   *setup root password:
    mysqladmin -u root password ***(this is new password)

    *run:
    mysql -u root -p

    *exit:
    \q

    *commands:ep t
    show databases;

    drop database ***;

2. Tomcat:

    *install:
        yum -y install tomcat5 tomcat5-webapps tomcat5-admin-webapps

    *You can find these packages using
        yum list available tomcat5*
        or
        yum search tomcat5

    *Start:
        service tomcat5 start
       
    view:   http://localhost:8080/.

    *location:r
         /usr/share/tomcat5 .
        *setting:
            "$CATALINA_HOME".

3. JDK:

     * Originally, centOS only install jre. so we need install jdk by ourselves.
     *To install from the command line:

$yum install java-1.6.0-openjdk-devel

You can also install all the OpenJDK 6 packages, including the API documentation, by using the wildcard java-1.6.0-openjdk*.

      *location:         /usr/lib/jvm...
      *check:  java -version