Linux

When sending additional data using the Sigqueue transmit signal, you need to set act.sa_flags = Sa_siginfo;The shell is an instruction parser outside the core program kernel, a program, and a command language and programming language.Soft and Hard

LS-the contents shown in L are as follows:-rw-r--r--. 1 root root 192 Jan 09:55 text.txt-10 characters to determine what different users can do with a file-the first character represents a file (-), Table of contents (d), link (l)-the remaining

$ crontab-eExample: Execute at two o ' clock every day0 2 */1 * */usr/bin/python/www/tbktsh/sendms.py &>/dev/null* * * * * Root run-parts/etc/cron.hourly # every hour to execute scripts within/etc/cron.hourly, "run-parts" This parameter refers to

1 2 3 4 Step through ReadingThe company is using Linux to build servers, Linux installation software can use Yum to install a dependency package is a very simple and happy thing, so here is a brief introduction to Linux installation

The second week how the operating system works the first section of the function call stackStored program computers: A framework for all computer infrastructuresStack: A basic part of a computer that has a stack when the computer has only machine

learn my brother asked me to start the process of Linux, suddenly was thunder, unexpectedly forget so thorough, the head floated 6 words-"Years is to kill pig knife", so bad fill, write log, at least the principle of things can not be lost,

Add a virtual IP address to CentOS7 This blog is written because this technology is needed later when keepalived is used to achieve Nginx high availability. The role of virtual ip in high availability will be discussed later. Today, let's look at

CentOS Virtual Machine enters rescue mode Right-click the VM and selectPower supply-Enter the Bios when the power is turned on. After entering the BiosUnder BootCD-ROM Drive moves to the top, and then pressPress F10 to save and restart Enter

Set sudo permissions for common centos users Create a common test user test under the root user, switch to the test user, and run mkdir or rm-rfPermission denied may occur because the user has no root Permission. [test@iZ2513wqj05Z app]$ mkdir

Example of an open port for iptables in CentOSThe CentOS system is highly efficient and stable when running as a website server. In windows, the system firewall can be used to restrict access from external computers to server ports. In Linux,

Detailed explanation of netstat commands in CentOSIntroduction The Netstat command is used to display various network-related information, such as network connection, route table, Interface Statistics, masquerade connection, and Multicast member

Bind multiple NICs to bond in CentOS 7 # Concept When the server has multiple NICs, you can use bond to implement multiple NICs and use them together; # Mode Mode 0: load balancing (round-robin) Support: Switch required Load Balancing :

Use tcpdump to capture packets in CentOS Tcpdump is used to capture packets in the CentOS system. First of all, check whether there is any installation. If not, use yum for installation. Tcpdump is a commonly used packet capture tool in linux

CentOS Optimization-iptables firewall processing and O & M ideas 1. Enable Firewall: ① Takes effect permanently after restart: chkconfig iptables on ② It takes effect immediately and becomes invalid after restart: service iptables start

The CentOS virtual machine needs to access the Internet to quickly configure IP addresses.If only virtual machines need to access the Internet, it is very simple.1. Go to the Centos system and view the network configuration.Run ifconfig-.2. Enter

Introduction to user permission assignment configuration in CentOS Introduction to user permission assignment configuration in Centos (Linux) When it comes to permission assignment, it is vital for a service to run normally. One common saying in an

Change the NIC name of centos7 to eth0 Because we often switch between centos6 and centos7, we feel that the NIC name of centos7 is too long and inconvenient, so we want to get the same name as 6. If you want to change the network card name to eth0

Linux practice (11) ---- shell monitoring server performance --- comprehensive application I have learned some monitoring scripts and practical functional scripts. This chapter is a comprehensive article that combines the content I learned to

Turning git through --- using RecyclerView to achieve the folding effect sectionedexpandablegridrejavaserviewToday, there is no P1, because the soy sauce is too much a year ago, and the accumulation of things is now a bit of a sense of urgency,

Locate abnormal web traffic: iftop + tcpdump + wireshark, iftoptcpdump A simple O & M experience.Scenario: abnormal traffic occurs on the web server, and large traffic occurs during interactions in the web Cluster. You need to locate specific http