/Dev/random and/dev/urandom notes, devurandom1. Basic Introduction
/Dev/random and/dev/urandom are random Pseudo devices provided in Linux. The tasks of these two devices are to provide random byte data streams that are never empt
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1. Basic Introduction
/Dev/random and/dev/urandom are Random Pseudo devices provided in Linux. The tasks of these two devices are to provide random byte data streams that are never empty. Many decryption and security applications (such as SSH keys and SSL keys) require random data streams they provide.
The difference
1. Basic Introduction/dev/random and/dev/urandom are random pseudo-devices provided in Linux systems, and the task of both devices is to provide a random byte stream that is never empty. Many decryption programs and security applications (such as SSH Keys,ssl Keys, etc.) require the random data streams they provide.The difference between the two devices is that/
Random numbers in Linux can be generated from two special files, one/dev/urandom. The other is/dev/random. the principle of generating random numbers is to use the current system's entropy pool to calculate a fixed number of random bits , and then return these bits as a byte stream. entropy Pool is the current system of environmental noise , entropy refers to a s
If you want random data in a Linux/Unix type OS, the standard way to do so is to use/dev/random or/dev/urandom. these devices are special files. they can be read like normal files and the read data is generated via multiple sources of entropy in the system which provide the randomness./Dev/random will block after the e
Random numbers in Linux can be generated from two special files, one/dev/urandom. The other is/dev/random. The principle of generating random numbers is to use the current system's entropy pool to calculate a fixed number of random bits, and then return these bits as a byte stream. Entropy pool is the current system of environmental noise, entropy refers to a sys
1, Introduction--From the wiki interpretation/dev/null:In a Unix-like system, a/dev/null, or empty device, is a special device file that discards everything written to it (but reports a successful write operation) and reads it immediately to get an EOF.In programmer jargon, especially in Unix jargon,/dev/null is called a bit bucket or black hole. Empty devices ar
Detailed description of/dev/null and/dev/zero files, solutions for accidental deletion of/dev/null and/dev/zero, and disk I/O testing using/dev/zero1. Introduction-explanation from Wikipedia/dev/null:
In Unix-like systems,/
For details about the/dev/null and/dev/zero files, and solutions for accidental deletion of/dev/null and/dev/zero, and the disk I/O Testing Method Using/dev/zero, disk deletion and recovery by mistake1. Introduction-explanation from Wikipedia/
1. Please check the information to understand these terms:/dev/hda,/dev/hdb,/DEV/SDA,/dev/sdb, what is the difference between them?A: Hda generally refers to the IDE interface of the hard disk, HDA refers to the first hard disk, HDB refers to the second hard disk, etc.; SDA refers to the SATA interface of the hard disk
By default, there are always three files open, standard input (keyboard input), standard output (output to screen), standard error (also output to screen), and their respective file descriptors are 0,1,2. So let's take a look at the differences between the following redirection methods:>/dev/null 2>1In fact, it should be equivalent to this: 1>/dev/null 2>/dev/nul
1. Serial Port Terminal (/dev/ttysn)The serial port terminal (serial port terminal) is a terminal device connected by a computer serial port. The computer regards each serial port as a character device. For some time, these serial port devices are usually called terminal devices, because at that time they were used to connect terminals. The device names corresponding to these serial ports are/dev/TTS/0 (or/
Tags: description command gadget should--standard standard output dev fileThis article was reprinted from: 11595985By default, there are always three files open, standard input (keyboard input), standard output (output to screen), standard error (also output to screen), and their respective file descriptors are 0,1,2. So let's take a look at the differences between the following redirection methods:>/dev/nu
By default, there are always three files open, standard input (keyboard input), standard output (output to screen), standard error (also output to screen), and their respective file descriptors are 0,1,2. So let's take a look at the differences between the following redirection methods:>/dev/null 2>1In fact, it should be equivalent to this: 1>/dev/null 2>/dev/nul
1./dev/mtdn: In the MTD architecture of Linux, The MTD partition implemented by the system correspondsCharacter DeviceWhich contains some IOCTL and supports many commands, such as memgetinfo and memerase.
Tools such as flash_eraseall in MTD-util are implemented based on these IOCTL to implement some flash operations. For example, in flash_eraseall of MTD:
If (IOCTL (FD,Memgetinfo, Meminfo )! = 0 ){Fprintf (stderr, "% s: Unable to get MTD device info/
Use
/Dev/null
Set/Dev/nullIt is regarded as a "black hole". It is very equivalent to a write-only file. All the content written to it will be lost forever. However, if you try to read the content from it, nothing can be read. However,/Dev/nullCommand Line and script are very useful.
DisableStandard output.
1 cat $ FILENAME>/
Prerequisite: The computer has Nodejs and NPM installed, and the project is a ZIP package that is downloaded directly. The error step is 1:cd/d directory; 2. NPM ren dev-------> Errors are as follows:> Webpack-dev-server--inline--progress--config build/webpack.dev.conf.js' Webpack-dev-server ' is not an internal or external command, nor is it a running programor
Webpack-dev-serverwebpack-dev-serveris actually the equivalent of enabling one express Http服务器+调用webpack-dev-middleware . Its role is mainly used to servo resource files. This Http服务器 and the use of the client websocket Communication protocol, the original file changes, webpack-dev-server will be used Webpack real-time
Name
Random, urandom-kernel random number source DevicesDescription
The character special files/Dev/randomAnd/Dev/urandom(Present since Linux 1.3.30) provide an interface to the kernel's random number generator. File/Dev/randomHas Major device number 1 and minor device numbe
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