if not equal

 Ethernet ports have 3 types of links: access, trunk, HybirdAn access type port can only belong to 1 VLANs for connecting to a computer port;Trunk type port can allow multiple VLANs through, can receive and send multiple VLAN packets, generally used

1, installation Zabbix-agentYum-y Install zabbix-2.4.8-1.el6.x86_64.rpm zabbix-agent-2.4.8-1.el6.x86_64.rpmInstallation of the above two packages will be generated in the/ETC/ZABBIX/ZABBIX_AGENTD.D directory userparameter_mysql.conf This

Modbus an industry-commonly used communication protocol, a communication convention. Modbus protocol includes RTU, ASCII, TCP. One of the most commonly used modbus-rtu, relatively simple, on a single-chip computer is easy to achieve. Although the

Transfer statement Statements in a program are usually performed in sequential direction, or in the direction defined by the statement function. If you need to change the normal flow of your program, you can use the transfer statement described in

GitHub Source: Github.com/z521598/redis-lockImplementation principle: 1.setnx Redis's setnx Directive (document reference), setnx means set if not eXists, command format: setnx $key $value If this key does not exist, it is set to value, the return

Installing the Introduction module Installing the MySQL module sudo apt-get install python-mysql Introducing modules into a file import MysqldbConnection object Used to establish a connection to the database

This article brings the content is about Java in the implementation of the principle of hashmap, there is a certain reference value, there is a need for friends to refer to, I hope you have some help. 1. HashMap Overview:HashMap is a non-synchronous

Packaging Observe the previous file discovery, except that the SQL statements and parameters are different, the other statements are the same Create a mysqlhelper.py file, define a class #Encoding=utf8ImportMySQLdbclassmysqlhelper (

A database is a warehouse that organizes, stores, and manages data according to its structure, and each database has one or more different APIs for creating, accessing, managing, searching, and replicating the saved data. Here are some terminology

MySQL uses the where command to qualify data query criteria.Syntax: SELECT Property 1, Property 2 from table name WHERE condition 1 OR Condition 2 and Condition 3Description: Where the same applies to update, delete and other commands;Using or, and

Paradigm:1NF: First paradigm. Relational mode r each value in the domain of all attributes is no longer decomposed.2NF: Second paradigm. If R is the first paradigm, and every non-primary property in R is dependent on a candidate key of R.

JDBC needs to operate the database through the connection database connection. The creation of a database connection is expensive, and we cannot create a database connection every time an SQL statement is executed, typically through a database

The test command in the Shell is used to check if a condition is true, and it can be tested in three aspects of numeric, character, and file.Numerical testParameter description-eq equals True-ne is not equal to true-GT is greater than true-ge is

If statement formatIf conditionThenCommandElseCommandFi, don't forget this ending.If statement forget the end fiTest.sh:line 14:syntax error:unexpected End of fi if three conditional expressionsIfCommandThen ifFunctionThenCommand execution succeeds,

12345678910111213141516171819202122 i2000:~ # lscpuArchitecture:          x86_64CPU op-mode(s):        32-bit, 64-bitByte Order:            Little EndianCPU(s):                8On-line CPU(s) list:   0-7Thread(s) per core:    2Core(s) per socket:

1[Email protected]:~$ cat/proc/Cpuinfo2processor:03VENDOR_ID:Genuineintel4CPU Family:155Model:26Model Name:intel (R) Pentium (r) 4 CPU 3.00GHz7Stepping:98microcode:0x179CPU mhz:2992.615TenCache size:512KB OnePhysical id:0 ASiblings:2 -Core id:0 -CPU

If you've been using Linux for a long time, then you know that Linux has changed several strategies in the case of device files. Early in Linux, the device files were just plain files with the appropriate set of attributes, created by the Mknod

Storage containers commonly used in Java are collections of arrays, and each container is stored in a different form and structure.Arrays are the most basic containers, and there are three ways to create an array, such as the following:int[] arr =

A string (string) is a finite sequence of 0 or more woo characters, also called a string.Explanation of the definition:?? The number of characters in a string n is called the length of a string, and the definition of "finite" means that the length n

8.1 Atomic access: Interlocked series functions (interlock in English for interlocking meanings)(1) Principle of atomic access① Atomic Access : Refers to a thread that accesses a resource while ensuring that no other threads are accessing the