[Linux] RHCE exam preparation review network communication netstat and ping commands

netstat command netstat command comes from the abbreviation of the English phrase "network statistics". Its function is to display various network related information, such as network connection status, routing table information, interface status, NAT, multicast members, etc. netstat command is not only applied to Linux system, but ...

Posted by perrij3 on Sun, 22 May 2022 03:35:27 +0300

5 kernel timer programming

Like Linux interrupt, the programming of kernel timer only needs to call the API functions provided by the kernel. After the clock interrupt occurs, the kernel will check whether each timer expires. After expiration, it will put its bound timer processing function to the bottom half for execution. Kernel timer essentially depends on hardware ti ...

Posted by bad_gui on Sun, 22 May 2022 01:25:07 +0300

Docker installation and common commands

Docker installation and common commands 1, docker installation 1.yum update yum update 2. Install required packages Yum util provides the yum config manager function, and the other two are dependent on the devicemapper driver yum install -y yum-utils device-mapper-persistent-data lvm2 3. Set yum source yum-config-manager --add-repo ht ...

Posted by NFWriter on Sun, 22 May 2022 00:50:52 +0300

Experiment 4 - tracking and statistics of process running track

1, Experimental purpose Master multi process programming technology under Linux; Visualize the concept of process by tracking the running track of process; The algorithm can be further compared with the actual scheduling process on the basis of quantitative data, so as to further understand the scheduling algorithm and obtain the actual operat ...

Posted by jmandas on Sat, 21 May 2022 11:10:40 +0300

Use of udev and mdev under linux

There are three kinds of device file systems under linux: devfs, udev and mdev. 1, devfs devfs was introduced by Linux 2.4 kernel, which was highly praised by many engineers. Its emergence enables device drivers to manage their own device files independently. Specifically, devfs has the following advantages: 1. You can create a device file in t ...

Posted by glennn3 on Sat, 21 May 2022 07:48:07 +0300

Redis data type (hash type)

hash type and operation ① Overview The hash type in Redis can be understood as a map container with String Key and String Value, so the hash type is suitable for storing value object information. Such as Username, Password or Age. Even if there are only a few fields in the hash, its data only takes up a small amount of disk space. Each ha ...

Posted by daniel_grant on Sat, 21 May 2022 04:01:06 +0300

Common Linux operations

Common Linux operations   1. Run sh file The first method: First you have to open a terminal. Then enter sudo su Then enter the password. This has achieved root User permissions. Then find the fileFirst, check whether the file has execution permission. If not, change the execution permission of the file, and then carry out the remaining op ...

Posted by olko on Fri, 20 May 2022 08:50:27 +0300

Shell script integer value comparison, logic test, if statement

1. Conditional test operation [conditional expression] (1) document test[file or directory]-d: Whether the directory is directory (test) -e: Test whether the directory or file exists (Exist) -f: Test whether it is a file -r: Test whether the current user has permission to read, -w: Test whether the current user has permission to write -x: T ...

Posted by Sneo on Fri, 20 May 2022 07:41:43 +0300

Connecting MySQL database with Linux (C + +)

1, Environmental installation The first is the installation of MySQL, which is directly installed only with apt get command (this method is recommended here, because it does not need to link the relevant path when compiling later programs) sudo apt-get install mysql-server After my installation, the relevant header files and dynamic lib ...

Posted by posidon on Fri, 20 May 2022 01:31:35 +0300

Use chroot to restrict SFTP users to the home directory

In this tutorial, we will discuss how to restrict SFTP users to their home directory or specific directory. This means that users can only access their respective home directories, not the entire file system. It is important to restrict users' home directories, especially in a shared server environment, so that unauthorized users will not pee ...

Posted by wih on Thu, 19 May 2022 14:27:23 +0300