Linux

Linux boot process: 1. Press the first start step of the power supply: Start firmware → POST power-on self-check Check the hardware loading status, such as the keyboard and memory. It has nothing to do with the operating system. Therefore, when you

When a process captures and processes the signal, the command sequence being executed by the process is temporarily interrupted by the signal processing program. It first executes the commands in the signal processing program. If it is returned from

The function of the abort function is to terminate an abnormal program. #include abort( This function sends the SIGABRT signal to the calling Process(The process should not ignore this signal ). According to iso c, calling abort will deliver an

1. check user identity You can use the following commands to learn about your identity. Who: Query current online users Groups: query the user group Id: displays the current user information Finger: Query user information 2. Add a user Add command

After logging on to linux locally, the logon message is from/etc/issue and/etc/motd. After logging on to linux via telnet, the logon message is from/etc/issue.net and/etc/motd. Therefore, you can add content in/etc/motd so that you can display your

I. File structure To store and read files on the device, we need to create a file system on the partition. The file system records directories and files, which are called the file structure. In Linux, each file system is interpreted as a directory

1. install vsftpd, as shown in: sudo apt-get install vsftpd 2. Check whether the local machine can connect to ftp As shown in, what should I do if I find login failed? Let's take a look at the vsftpd configuration file vsftpd. conf. Don't

A process whose parent process has been terminated is calledOrphan process), This process is "adopted" by The init process ". The entire process group can also become an orphan ". Orphan process group): The parent process of each member in the

Redirection 1.1. The redirection symbol of the correct content > The output is redirected to a file or device to overwrite the original file. >! The output is redirected to a file or device to forcibly overwrite the original file.> The output is

A method is required to notify the kernel of which process group is the foreground process group, so that the terminal device driver can know where the terminal input and terminal signals are sent. # Include -tcsetpgrp (- The tcgetpgrp function

3.4 Disk bottlenecks Disk bottleneckThe disk subsystem is often the most important aspect of server performance and is usually the most common bottleneck.However, problems can be hidden by other factors, such as lack of memory.Applications are

I. Device Files The device exists as a special file in Linux Block Device Files Character (character) Device File Location of the device file View device types Ii. virtual console and user identity Switching There are 12 virtual

3.3 memory bottleneckOn a Linux system, using programs run at the same time.These programs support multiple users, and some processes are more used than others.Some of these programs use a portion of memory while the rest are "sleeping ."When an

I. Introduction to Shell Shell: the command line interpreter. It is a media used to communicate with the system. There are various shells in Unix systems. Linux uses bash as its default Shell. The shell records that can be used by the system are

When a user logs in, the following two configuration files are read: 1)/etc/profile: The global configuration file of the system. It is best not to modify this file. 2 )~ /. Bash_profile or ~ /. Bash_login or ~ /. Profile: Private configuration

You do not need to remember the command for disk partition-fdiskfdisk, because after entering m, you will see detailed help information, as shown below: [root@lx15 /data ]# fdisk /dev/sdaThe number of cylinders for this disk is set to 36404.There is

VII. Command Line expression Command Line output -- "" Treat a string as a string. If a string contains characters with special meanings, It is escaped. Double quotation marks cannot be \ $ '! Special Functions of symbols are prohibited

To learn about linux, we must first install linux. Here I have provided a tutorial on the entire process of linux installation, hoping to help you successfully install linux. This linux is installed on a virtual machine. If you want to download a

Rsync Introduction Rsync is a data image backup tool in unix-like systems-remote sync. Rsync is a very powerful tool, and its commands have many special options. The following describes the options one by one. Its features are as follows: Images can

Iso c defines system functions, but its operations are highly dependent on the system. POSIX.1 includes the system interface, which extends the iso c Definition to describe the running behavior of the system in the POSIX.1 environment. #include