fcntl

There are two ports that can be controlled for serial blocking (simultaneous control of Read and write): One is the opening of the serial port, whether the open function with O_ndelay, the second one can be opened after the serial port through the

How to port programs containing flock to Solaris Author: BadcoffeeEmail: blog.oliver@gmail.comBlog:Http://blog.csdn.net/yayong2005Year5Month A friend's Linux source program contains the following calls:Flock (FD, lock_un) There is no problem in

1. the kernel uses three data structures to indicate opened files. The relationship between them determines the impact of one process on another process in file sharing. (1) each process has a record item (task_struct) in the progress table,

  1. the kernel uses three data structures to indicate opened files. The relationship between them determines the impact of one process on another process in file sharing.   (1) Each process has a record item (task_struct) in the progress table,

First, Lseek functionEach open file has a "current file offset" associated with it. It is usually a non-negative integer used to measure from the beginning of the fileThe number of bytes computed. Typically, read and write operations start at the

I. Opening and creating a file Open the function to open or create a file and return the file descriptor.# Include Int open (const char * filename, int Oflag,.../* [model_t mode] */);Parameter description:Path Name of the file opened or created by

1. SignalNginx uses a lot of signals when managing master and worker processes. The first 31 signals that are defined by Linux are the most commonly used, and Nginx uses them by redefining the processing of some of these signals, such as receiving a

Function Description: According to the file description to manipulate the characteristics of the file. #include #include int fcntl (int fd, int cmd); int fcntl (int fd, int cmd, long arg); int fcntl (int fd, int cmd, struct flock *lock);

Recently encountered a problem writing a Python projectThere is a Python script like this:1 Scripting FeaturesA Monitor the real-time traffic of the network card, if the traffic exceeds the set threshold to increase the bandwidth (purchase bandwidth

1. Advanced socket functions getsockopt and setsockopt Int getsockopt (INT sockfd, int level, int optname, void * optval, socklen_t * optlen)Int setsockopt (INT sockfd, int level, int optname, const void * optval, socklen_t * optlen) LevelSpecifies

Generally speaking, reading data from ordinary documents, whether you are using fscanf,fgets or read, will definitely return within a limited time. However, if you read the data from a device, such as a terminal (standard input device), read must

Python calls external sub-processes and achieves asynchronous standard input and output through pipelines. we usually encounter the following requirements: A complex functional module is implemented through C ++ or other lower-layer languages. you

How to lock files There are three different file locks, all of which are "consulting", that is, they rely onProgramBetweenCooperation, so the consistency of all program blocking policies in a project is very important when your program needsBe

In linux low-level file programming, file locks are an important part of multi-user multi-task operating systems. When updating a file, you expect to use a mechanism to prevent both processes from simultaneously updating the file in the same region,

Advanced IO non-blocking IO allows us to call IO operations such as open, read, and write without permanent blocking. Advanced I/O non-blocking IO Non-blocking I/O allows us to call I/O operations such as open, read, and write without permanent

Python daemon and script Singleton running details, python daemon This article mainly introduces the Python daemon process and script Singleton running. I think it is quite good. I will share it with you and give you a reference. Let's take a look

  1. getsockopt and setsockopt Functions These two functions are only used for sockets: # Include int getsockopt (int sockfd, int level, int optname, void * optval, socklen_t * optlen); int setsockopt (int sockfd, int level, int optname, const void

PassFcntlSet File Description Descriptor PropertiesFcntl is the use of F_SETFL,F_GETFL, set the file of flags, clogging is set to non-clogging, non-clogging is set to plug (this can be encapsulated as a basic function in server development)1. Get

1.1 file descriptorThe file descriptor (fd) is equivalent to the file handle in windows programming. It enables a non-negative integer to reference an open file.In Unix, the file descriptor 0 (STDIN_FILENO) is the standard output, 1 (STDOUT_FILENO)

I. Unix domain Protocol The Unix domain protocol is not an actual protocol family. It only communicates with a client-server on the same host, one method of using the same API (set interface or XTI) as communication between customers and servers on