minion io

Synchronous and asynchronous Io, blocking and non-blocking Io Many times we often see synchronous and asynchronous, blocking, and non-blocking. In some cases, the synchronization and blocking operations are placed with equal signs. Asynchronous and non-blocking draw an equal sign. In fact, this is not correct. Synchronization is not equal to blocking, while Asynchronization is not equal to non-blocking. Nex

Sys_select ()------> Do_select ()The final call to the file descriptor fd corresponds to the struct file type variable of the struct file_operations *f_op of the poll function.The function that poll points to returns information that is currently read and written.1) returns read and write information if it is currently readable or writable.2) If it is not currently read/write, block the process and wait for the driver to wake up, call the poll function again, or return the timeout.3, the driver

[] args)throwsunsupportedencodingexception {Try { //1. Declaring an input streamFileInputStream fis=NewFileInputStream ("D:/test/s1.txt"); //2. redirectionsystem.setin (FIS); //3. Read the contents of the system.in standard input streamBufferedReader br=NewBufferedReader (NewInputStreamReader (system.in, "gb2312"));//Set character encoding//4. Output the contents of the system.inString line=NULL; while((Line=br.readline ())! =NULL) {System.out.println (line); } //5. Close

layout algorithm used by most file systems, the files in each directory tend to be distributed adjacent to the disk.2,inode number: Using inode sorting is more efficient than path sorting, and in general, the order of the inode means the order of the physical blocks.3, the physical block of the file: the physical block is obtained through the file logical block, and then sorted again. The first step is to determine the number of blocks in the file. This can be done through the stat () call. Sec

There are two types of IO in Linux programming, one is the IO function provided by the standard library fopen, Fread, fwrite. A class is the System interface function read, write, and so on. This article explains the differences and linkages between the two types of IO.Difference:First look at the definitions of the two types of IO functions:Fread: size_t fread

Java IO stream, java IO stream character Refer stream: it also reads binary files, which will be decoded into characters that we can understand.Bytes stream = byte stream + Decoding(1) character input stream: Reader: It is the root class of the character input stream and is an abstract class. FileReader: file character input stream, which reads strings.Usage:1. Find the target file2. Establish a data channe

Reprint Please specify source: http://www.cnblogs.com/Joanna-Yan/p/7723174.htmlPrevious: Java IO programming Full Solution (ii)--traditional bio programmingIn order to solve the problem that the synchronous blocking I/O faces a link that requires a threading process, someone later optimizes its threading model, and the backend uses a thread pool to handle requests from multiple clients, forming the number of clients m: the proportional relationship of

physical address from the table, and then generates the bus sequence to get data. (2) Addressing Method1) peripherals are all performed by reading and writing registers on the device. The peripherals register is also called "I/O port", and the IO port has two addressing methods: Independent addressing and unified compiling. Unified addressing: the I/O registers (I/O Ports) in the peripheral interfaces are the same as those in the primary storage unit

Alertable Io provides a more effective asynchronous notification format. Readfileex/writefileex provides a callback function (APC process) when sending an IO request. After the IO request is complete, the callback function will be executed once the thread enters the alarming status.The following five functions enable the thread to enter the alarm status:SleepexWa

?12 binary io (binary io)In the previous article we learned about read-only and line-by-read functions.If we are reading and writing binary files, and want to read and write the entire file content, these two functions can be implemented, but it is obviously cumbersome and many cycles are obviously inefficient.To address this scenario, the standard IO library pro

This is a creation in Article, where the information may have evolved or changed. Interface Definition-BASIC interface //-----------------------------------------------------------------------------//============================== ===== Basic Interface ===================================//----------------------------------------------------------------- The------------//Reader interface is used to output its own byte data. There is only one duck method read. Parameter P: reads the data stream

;15//Determines whether a prime number is a public boolean isprime (i NT N) {(int i=2;iIf the stream is not buffered, the program reads a data and writes a data. This greatly affects the efficiency in a program with large data volumes. The buffer stream function is to write the data to the buffer, wait for the buffer full, and then write the data into the file. So the efficiency is greatly improved.Original address: http://www.cnblogs.com/liuling/archive/2013/05/07/InputStreamAndOutputS

1. bool exist = system. io. directory. exists (CFG. xmlproductpath + @ "\ mobile \"); // determines whether a folder exists 2. directory. createdirectory (CFG. xmlproductpath + @ "\ mobile \"); // create a mobile folder 3. string [] dirs = NULL; dirs = directory. getfiles (CFG. xmlproductpath + @ "\ mobile \"); // return the file name in the mobile folder 4. fileinfo = new fileinfo (dirs [I]); // obtain file information (including path packaging)

I. Io and stream Data input and output (I/O for input/output)The input and output of standard input devices and standard output devices are referred to as standard I/OThe input and output of files stored on an external disk are referred to as files I/O.The input and output of the specified string bucket in the memory are referred to as string I/O. The process of data input and output can be visually viewed as a stream.The operation for retrieving dat

"); In fact, you can not refresh ps.close (); } Character Print stream: public class Printwriterdemo {public static void Main (string[] args) throws Exception { PrintWriter PS = new Prin Twriter (New File ("File/out.txt")); Ps.write ("ABC"); Ps.print (false); Ps.println (); Ps.print ("Layne"); In fact, you can not refresh ps.close (); } Formatted output in the print stream (printf method): System.out.println (); actually equivalent to printstream PS = Syst

Basic IO operations, text data IO operationsJava standard IO (input/output) operations Packageday07;ImportJava.io.FileOutputStream;Importjava.io.IOException;/*** java standard IO (input/output) operation * Input stream Inputstrean: used to read data from the data source into the program * output stream OutputStream: us

:writer class is an abstract class of character output streams, and the implementation of all character output classes is its subclass.The 6:file class is the only object in the IO package that represents the disk file itself. Create, delete, and rename files through file. The main function of the file class object is to get some information about the text itself. such as the directory where the text resides, the length of the file, read and write per

user programs (fgets parameters require a user row cache pointer). No matter what the above is understood, remember one point: One advantage of using standard I/O routines is that there is no need to consider caching and optimal I/O length choices, and it is no more slow than directly calling read and write. File operation with cache is the implementation of standard C library, first call with cached file operationfunctionThe standard library automatically allocates memory and reads a fixed amo

The system. Io. File class and system. Io. fileinfo class provide various operations on files. The system. Io namespace must be referenced during use. The following describes the main attributes and methods of a program instance. (1) file opening method: file. open ()The statement of this method is as follows:Public static filestream open (string path, filemode M

How to Use socket. io and nodesocket. io in node express Server. js Code Copy codeThe Code is as follows:Var express = require ("express ");Var http = require ("http ");Var sio = require ("socket. io ");Var app = express ();Var server = http. createServer (app );Var fs = require ("fs ");App. get ("/", function (req, res ){Res. sendfile (_ dirname + "/index.html "