fcntl

Today, when the Internet is quite popular, chatting on the Internet is already common for many "Online worms. Chat Room programs are the simplest multi-point communication program on the Internet. There are many implementation methods for chat rooms,

Article title: fcntl: F_SETLKW: Norecordlocksavailable in the apache error log. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems,

First, Fcntl function Function: Manipulate file descriptors to change the properties of an open file int fcntl (int fd, int cmd, .../* arg */); The value of CMD can be as follows: Copy file descriptor F_DUPFD (Long) Set/Get File descriptor

Today, when the Internet is quite popular, chatting on the Internet is already common for many "Online worms. Chat Room programs are the simplest multi-point communication program on the Internet. There are many implementation methods for chat rooms,

#include #include #include #include #include #include #include #define ERR_EXIT(m) do { perror(m); exit(EXIT_FAILURE); }while(0)void activate_nonblock(int fd);void deactivate_nonblock(int fd);int main(int argc, const char *argv[

// The lock1.c/* program first creates a file and opens it in a readable way. Then, it adds some content to the file, and then sets two regions in the file, the first region is 10-30 bytes and the shared lock is used. The second region is 40-50

#include int Fcntl (fd,f_getlk/f_setlk/f_setlkw,struct flock *flockptr);F_GETLK: Tests whether the lock described by flockptr conflicts with an existing lock. Conflicts: Existing locks are written in flockptr; not conflicting: flockptr

#include #include #include #include int my_dup ( INTFD,INTFD2) {    if (FD==FD2)              return fd2;    int n= 0;    int  look= 0;    int i_count= -1;    int *  Fd_arr=null;    fd_arr= (int *) malloc (1024*sizeof (int));     while ( (N=dup

#include #include #include #include #include #include #include #define ERR_EXIT (m) do {perror (M); Exit (Exit_failure); }while (0) void activate_nonblock (int fd), void deactivate_nonblock (int fd), int main (int argc, const char *argv[])

7.2 File Lock This is a file lock for Linux and the code is downloaded in the file lock code. File locking is a very important part of a multi-user, multitasking operating system.programs often need to share data, which is usually done through a

1.dup and DUP2 functions#include int dup (int fd);int dup2 (int fd1,int fd2);Two is a description of the copy of an existing fileTwo function return: If the new file is successfully described, if the error is-1;The new file descriptor returned by

Close (close the file) Related functions Open, fcntl, shutdown, unlink, fclose Header file # Include Define functions Int close (int fd ); Function Description If the file is no longer needed after

Shing Email: [Email protected] Blog: Http://blog.csdn.net/qifengzou Date: 2014.09.12 Reprint please indicate the CSDN blog from "Chifeng" 1 OverviewA system that contains multiple threads/processes will often have multiple

I. What is file lock? No one will be unfamiliar with the word lock, because there are a lot of locks in our lives, and they play their role in all aspects, the lock function in the world can be summarized as one sentence, that is, to prevent some

1. System file read/writeTask Description:Write the program, read the Linux system file "/etc/passwd" content, and output to the screen. In the program directory, create a new file passwd and copy the contents of the "/etc/passwd" System file to the

One, what is file lockFor the word lock, we must not be unfamiliar, because we live in a large number of locks, they play its role in all aspects of the world, now the function of the lock can be summed up as a sentence, is to prevent some people do

0. preface this article describes the content involved in the ngx_process_events_and_timers function in nginx. I learned 14.2 non-blocking I/o14.3 record locks 14.7readv and writev Functions The record lock is used for the accept mutex

1. Basic concept of File lockLinux software, hardware resources are files (all files), files in multi-user environment is shareable.File locks are a mechanism used to solve shared use of resources: When multiple users need to share a file, Linux

Transfer from http://www.cnblogs.com/hjslovewcl/archive/2011/03/14/2314333.htmlThere are three different file locks, three of which are "advisory", which means they rely on theCooperation, so it is very important for all programs in a project to

Fcntl filehandle, function, scalar Implements the fcntl (2) function. You'll probably have to say Use Fcntl; First to get the correct constant definitions. Argument processing and value returned work just likeIOCTLBelow. For example: