unix system programming book

, generally use I/O multiplexing; It is possible for a client to handle multiple sockets at the same time, but relatively rare; If a server is to process TCP, but also processing UDP, the general need to use I/O multiplexing. If a server is to handle multiple services or multiple protocols, I/O multiplexing is generally used. I/O multiplexing is not limited to network programming, and many important applications need to use this technology as well

In this section, the Tell_wait and Tell_parent,tell_child in the book do not figure out exactly how the synchronization mechanism is implemented. proc/tellwait1.c 8-6#include "apue.h" static void Charatatime (const char *); int main (void) { pid_t pid; if (PID = fork ()) Lib/tellwait.c#include "apue.h" static volatile sig_atomic_t Sigflag; /* Set nonzero by sig Handler */static sigset_t Newmask, Oldmask, zeromask;static void sig_usr (int signo)/

Prepared to see the ambitious apue, but always feel like looking at a dictionary, a lot of places are introduced to the use of functions, but given the example is far less than the description of the function. And this book is still a tome. The 7th chapter of the process environment, process is a relatively important concept of program design, know that it is the general meaning, but in fact, there are a lot of details actually did not delve into, thi

UNIX Environment Advanced Programming book the error-handling functions that are often used by the sample programs. Save these functions in a file for easy learning and use. My_err.h #include My_log.h #include

This article describes how to apply a PHP script to correct the Linux or Unix system password. Required Tools and installation: you must install the following tools and software:-Shell script for password fixing;-Sudo access permission;-ApacheorLighttpdweb server;-PHP service This article describes how to apply a PHP script to correct the Linux or Unix

Recently, in a project, a TCP-based network programming for the server and client is required. Because the data returned by the server is not so timely, some latency needs to be done on the client, then you can read the data. The test results are as follows. First, let's take a look at a encapsulated read latency function: # Define err_exit (m) do {perror (m); exit (exit_failure);} while (0)/*** read timeout-read timeout detection function, excluding

the synchronization of threads is very important. threads can be divided into user-level threads and core-level threads. (1) The user-level thread is mainly to solve the problem of switching between the top and bottom, its scheduling algorithm and scheduling process is the user's own choice of decision, at run time does not need a specific kernel support, the operating system will provide a library function, including the creation of threads, schedul

header Files : #include Function Description:FILE * Popen (const char * command, const char * type); int pclose (file * stream);Description: (Refer to Advanced Programming for UNIX environments)the Popen () function creates a child process by creating a pipe, calling fork, and executes a shell to run the command to open a process. This process must be closed by the Pclose () function instead of the fclose

UNIX system programming 2 Use with Unix programming 2 01: Tree: # include

once the file changes, The structure of the second call might not be the right one.File name and path name truncationIf Name_max is 14 and the file name is exactly 14 characters, then any function that takes the pathname as a parameter cannot know what the file's original name is. The reason is that these functions cannot tell if a function has been intercepted.Modern file system support file name length can be 255, so for the vast majority of applic

In the network programming, is generally multithreaded programming, this arises a problem: data synchronization and sharing. The mutex and condition variables are the two most basic components to allow the data to be shared between threads or processes. They can always be used to synchronize multiple threads in a process.Before entering the mutex and the condition variable, we first introduce some related f

limited amount of information in the first two modes of communication, the process with Write permission can add new message to message queue according to certain rules, and the process with Read permission to message queue can read the message from Message queue.　　Semaphore (Semaphore): primarily as a means of synchronization and mutual exclusion between processes and between different threads of the same process. Shared memory: This can be said to be the most useful way to communicate between

Table of Contents 1 UNIX network programming-lock (2) 1.1 semaphores API 1.2 Implementation of semaphores mutex lock 1.2.1 The member variables are as follows: 1.2.2 implement the following member functions: 1.3 Implementation of the semaphore read/write lock 1.3.1 member variables of RWSem: 1.3.2 member functions of RWSem: 1.4 download the semaphore

. Start the terminal40. Enter the pathwatermark/2/text/ahr0cdovl2jsb2cuy3nkbi5uzxqvaxrjyxn0y3bw/font/5a6l5l2t/fontsize/400/fill/i0jbqkfcma==/ Dissolve/70/gravity/southeast "/>41. Compile and run42. Write a C + + code 1,CC43. Print statements, C + +44. Print out the results45. Drive HelloWorld#include #include Module_license ("Dual BSD/GPL");//Follow the Linux protocolstatic int hello_init (void){PRINTK (Kern_alert "Hello, world\n");//Print driver informationreturn 0;}static void Hello_exit (void

represents a thread that unlocks the mutex of another thread when unlocked to indicate when a thread unlocks a mutex that has been unlocked.the type of mutex can be managed through the Pthread_mutexattr_gettype function and the Pthread_mutexattr_settype function. 3. Read-Write Lock propertiesThe only property supported by the read-write lock is the process share property, which is the same as the mutex process share property and can be manipulated by the appropriate get and set functions.4. Bar

refer to any character or string except the character $, ', \ \.A single quotation mark is similar to a double quote, but a single quotation mark and its internal value are used as a new string if the special meaning is masked.boy= ' Boy ' echo, like ' $BOY ', ' echo ' like ' $BOY 'The contents of the two echo outputs are not the same, and the previous ECHO has a pair of single quotes.Anti-quote: The shell takes the contents of the backslash as a system