Linux

To view CPU, memory, and hard disk size under Linux:How to view CPUs1, cat/proc/cpuinfo or more intuitive to view the model of the CPU command: DMESG |grep-i XeonWays to view memory2. Cat/proc/meminfo or more intuitive command to view memory:

Nginx is a very important part of Linux, and learning how to use it will be very rare.Shutting down the firewall[[email protected] ~]# systemctl stop firewalld[[email protected] ~]# systemctl disable firewalld[[email protected] ~]# sed -ri

cat/etc/passwd CAT/ETC/PASSWD View all user information, details such as "Step two" Cat/etc/passwd|grep user nameThe Cat/etc/passwd|grep user name that is used to find a user, such as "Step three" Cat/etc/groupCat/etc/group View all group

　　1, User and user group concept:1. File owner2. User groups3. UserAfter you log on to Linux as root, execute ls-al and see information about the properties of the file-rw-r--r--, The 1th character indicates that the file is "directory, file or link

1. File Operation commands 1. Create a file The Touch command is in the same directory/bin/touch Touch FileName//Create an empty file2. Switch directories CD or CD ~//Back to home directory CD-Return to previous catalog CD!$ switch to

The process that counts the highest memory:PS aux | Grep-v PID | Sort-rn-k 4 | HeadTo count the processes with the highest CPU utilization:PS aux | Grep-v PID | Sort-rn-k 3 | HeadZombie Process:PS aux | grep defunct | Grep-v grepTo find the thread

Command format: Command Parameter ObjectParameters: 长格式 --help 短格式 -hObjects: Objects to be processed, directories, users, etc.1. Help commandsMan command name (used to view command usage and parameters)Command

1. Remote connection Server 1. View IP Address Ifconfig 2.IP configuration: (Redhat) Netconfig (Graphical configuration) 3. Restart the Network Service Service Network restart 4. Stop the firewall, you need to shut

There are 7 runtime run levels under LinuxRun Level 0 system shutdown state, the system default RunLevel cannot be set to 0, otherwise it will not start normallyRun Level 1 single user working status, root privilege, for system maintenance, remote

CentOS 7 system, does not differentiate between 32 bits and 64 bits.1.man Command tree structure displays command usage2. Command-help ibid., but not tree-shaped3.tree function: The tree structure displays subdirectories under a directory.Note: The

Operating system version: CentOS 6.10 x86_64View network card information obtained by the kernel[Email protected] ~]# DMESG |grep-inchETH1775: e10000000: Geneva:01.0: eth0: (Pci:66mhz: +-bit)xx: 0c: in: 6b:6e:1b1776: e10000000: Geneva:01.0:

1.ls-l listing the details of a file-rw-r--r--1 root root 13572 zabbix-release-3.4-2.el7.noarch.rpm-rw-r--r--: Permissions1: Multiple files using the same inode (for example: 1 files using the same inode)Previous root: Indicates the owner.Post Root:

A user-created command:# AddUser User Name# Useradd User Name1) The difference between Useradd and AddUserIn the CentOS system:Useradd and AddUser are no different, are created users, in/home automatically create user directory, no password, you

1. Download the JDK and Tomcat.Jdk:Http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.htmlTomcat:http://tomcat.apache.org/download-70.cgi2.JDK installation and configuration.(1) JDK installationRPM Package:# RPM-IVH

Command function:Chown the owner of the specified file to the specified user or group, the user can be either a user name or a user ID; a group can be a group name or a group ID; a file is a space-separated list of files to change permissions, and

Experimental methods: Open two virtual machines A and B,IP addresses are 192.168.222.12, 192.168.222.10, respectively Under virtual machine A, do the following to generate the public key and key: [[email protected] ~]# ssh-keygen -t rsa

1 Installing the VSFTPD component after installation, there is a /etc/vsftpd/vsftpd.conf file, which is the vsftp configuration file.[Email protected] ~]# yum-y install VSFTPD2 Add an ftp user This user is used to log on to the FTP server. [Email

    The top command is used to display the current process and other conditions of the system. It is a dynamic display process, that is, you can press the key to continuously refresh the current status, if the command is executed on the foreground,

Implementation Mechanism of Linux Pipelines In Linux, pipelines are frequently used communication mechanisms. In essence, an MPS queue is also a file, but it is different from a common file. The MPs queue can overcome the following two problems: ·

The source code is as follows: #include #include #include #include #include #include #include #include #include //#include "scull.h"#define SCULL_MAJOR 0 /* dynamic major by default */#define SCULL_NR_DEVS 4 /* scull0 through scull3 */#define