Linux

The Registration process for character devices in Linux is relatively straightforward. We can usually call the Misc_register () function to register a character device. A misc device is a character device that enables the ability of a character

Fork () function The only way to create a new process in Linux is to use the fork () function. The fork () function is a very important function in a Linux system, which is different from the one we've encountered before, because it looks like it's

System Performance analysis Tools The above sections describe several aspects of how Linux performance is affected and how to solve them, but how do you find out from the system that something is wrong with a certain aspect or a few aspects, which

Under Linux, the top tool can display the average CPU utilization (USER,NICE,SYSTEM,IDLE,IOWAIT,IRQ,SOFTIRQ,ETC.), which shows the utilization of each CPU. However, this situation may occur when the CPU utilization of each thread cannot be displayed,

First, grep, egrep, Fgrep command In this paper, we mainly introduce the basic parameters and usage formats and methods of the Egrep fgrep commands and regular expressions under the Linux system. (Note: The FG represents an example in the text) 1.1

First, when there is no data to read O_nonblock Disable:read Call blocking, the process suspends execution until the data arrives. The O_nonblock enable:read call returns a -1,errno value of Eagain. The sample program is as follows: /************

Each process has a TASK_STRUCT structure in the Linux kernel that maintains process-related information, known as a process descriptor, and in the operating system theory, the Process Control block (pcb,process). There is a pointer in the

LAMP refers to the Linux (operating system), Apache (HTTP server), MySQL (Database software) and PHP (sometimes referred to as Perl or Python) The first letter, generally used to build a Web server. Linux is free open source software, which means

With the development of network technology and the further deepening of network application, the campus network undertakes more and more applications from teaching, scientific research and management. The Campus Network Center, as the data storage

RedHat Linux provides firewall protection for increased system security. Firewalls exist between your computer and your network to determine which remote users on your network have access to the resources on your computer. A properly configured

As a mechanism of enforcing access control between network and system, firewall is an important means to ensure network security. Different firewall systems can be tailored to different requirements and application environments. Firewalls can be

1.NetworaManager: Fast switching between wireless and wired networks. Generally used for mobile terminals. 2.NetworkManagerDispatcher: Switch back and forth between multiple network environments, same as NetworkManager. 3.acpid: (no preset port)

1, the beginning The program must start with the following line (must be on the first line of the file): #!/bin/sh The symbolic #! is used to tell the system that the parameters behind it are the programs used to execute the file. In this example

SSH is not available because of/var/lib directory permissions A colleague of the morning said a server SSH login is not. Initially thought that the SSH service did not start, the execution service sshd status. Linux-34:/var/lib # service SSHD

Make is a very important compilation command, both in Linux and in UNIX environments. Whether you are developing your own projects or installing applications, we often use make or make install. With make tools, we can break down large development

In the Linux operating system, there is a system package that functions like "Add/Remove Programs" in Windows, but features are much better than "Add/Remove Programs", which is red Hat Package Manager (RPM). The toolkit was first launched by Red Hat

As a result of the project needs, in Linux virtual a Windows, after looking for some information, found that can be used as a VMware to achieve, of course, there are other virtual machines can be used such as Win4lin,bochs, but after a trial, only

Here's a list of keyboard shortcuts you can use to quickly perform common tasks. These actions are not limited to what is listed, but to learn more about the shortcut actions of the command line and keyboard. [Ctrl] + [Alt] + [Backspace] = Kill

As Linux continues to heat up in China, more and more people want to learn it. But the vast majority of people have been accustomed to a fool-like operation of Windows, it is very difficult for them to adapt to the operation of Linux. In particular,

A CentOS minimized installation machine, yum-y install ntpdate installation ntpdate sync time. Execute ntpdate time.nist.gov, unable to synchronize time with server, and the following error occurred: ntpdate[1897]: No server suitable for