1. 永久开启/关闭防火墙 在linux中防火墙是一个名叫iptables的工具 开启: chkconfig iptables on 关闭: chkconfig iptables off 即时生效,重启还原 开启: service iptables start 关闭: service iptable stop 2. 查看系统中是否安装了Postgresql rpm -qa|grep postgresql 查看服务的名称 service --status-all|grep postgres 3.…

Matlab basic operation: >> 5+6 ans = 11 >> 3*4 ans = 12 >> 2^6 ans = 64 >> 1==2 ans = 0 >> 1~=2 ans = 1 >> 1&&0 ans = 0 >> 1||0 ans = 1 >> xor(1,0) ans = 1 >> xor(1,1) ans = 0 >> who 您的变量…

The frequently used operation in Linux system    2017-04-08 12:48:09  1. mount the hard disk:  #: fdisk -l     %% use this operation to check how many and what disk it found in the computer. #: mkdir yiDongYingPan   %% mkdir a new file as the locatio…

In the past four blogs, we attached importance to the index, including description and comparison with usage of index. Now in this blog, we will mainly focus on the basic operation of index. such query, remove ,repair and so on. 1. View Index getInde…

Computer basic Computer 5 parts CPU Input Output Memory External storage device. CPU RISC: Reduced Instruction Set Computing, Each instruction is simple and efficient, but need multiple instructions when need to do a complex task. SPARC series of Sun…

1.  logic operation : '&&' and '||'  .For this two logic operations,its' results are inconclusive.the difference between this two logic operations  and others is that they don't change the data type of the operands and also don't change the data t…

mysql> select * from wifi_data where dev_id like "0023-AABBCCCCBBAA" ; 1.显示数据库列表.show databases;刚开始时才两个数据库:mysql和test.mysql库很重要它里面有MYSQL的系统信息,我们改密码和新增用户,实际上就是用这个库进行操作. 2.显示库中的数据表:use mysql: //打开库,学过FOXBASE的一定不会陌生吧show tables; 3.显示数据表的结构:descr…

mysql> select * from wifi_data where dev_id like "0023-AABBCCCCBBAA" ; 1.显示数据库列表.show databases;刚开始时才两个数据库:mysql和test.mysql库很重要它里面有MYSQL的系统信息,我们改密码和新增用户,实际上就是用这个库进行操作. 2.显示库中的数据表:use mysql: //打开库,学过FOXBASE的一定不会陌生吧show tables; 3.显示数据表的结构:descr…

1.如何启动一个命令行的hadoop客户端 任何一个Hadoop集群中的节点,只要有hadoop安装包,就可以通过# hadoop fs来启动 2.Hadoop基本命令格式 # hadoop  fs  -cmd  <args> 3.上传文件到HDFS 集群  hadoop fs  -put # hadoop  fs  -put   本地文件   hdfs文件      # hdfs文件的父目录一定要存在,否则不执行 # hadoop  fs  -put    本地文件/目录   hdfs目录 …

目录 . 引言 . Kill Process By Kill Command && SIGNAL . Kill Process By Resource Limits . Kill Process By Code Injection Into Running Process Via GDB . Kill Process By Using Cross Process Virtual Memory Modify To Crash Process && process_vm_wri…