fcntl

In Linux, there are two types of File Locking: one is to create a lock file through atomic operations, and the other is to allow access to this part of the content to be locked. 1. Lock files Many applications only need to be able to create a lock

Abstract: This section describes some basic operations on a process. Through this section, we will learn how to generate a sub-process, how the process changes its execution image, and synchronization of parent and child processes. We also learned

We often encounter the need to implement a complex functional module through C + + or other lower-level languages, and to build a Web-based demo and query data. Thanks to the power and simplicity of the Python language, the Flask framework and the

The program needs to update the file. Although most programmers know that unexpected things can happen when I am performing I/O, I often see some unusually naïve code. In this article, I want to share some insights into how I can improve I/O

File descriptor flags (currently there is only one close-on-exec):It is only a flag that is used when the EXEC function is called in a child process when the process is fork a subprocess. The meaning is whether to close the file descriptor before

The first is commonly used by several functions open, Read,write,lseek, closeOpen function function prototype int open (char * path,int oflag,...) The return value is a file descriptor. Path is the name of the filename oflage file is open by the

Ls-C/dev | head-5 LP * printerFD * Soft driveSD * SCSI device PartitionTty * Terminal The DSP file is a connection to the Sound Card/Dev/mouse: Read the file to read the mouse clicks and location changes. All file-related operations: open,

In Linux, find the library in which a function is located-Linux general technology-Linux programming and kernel information. The following is a detailed description. Regarding how to find out which library file a library function is in, I want to

simply write a small program to understand the mechanism of some signalsAlthough the combination of blocking and non-blocking operations and the Select method is sufficient for querying the device for most of the timeEnough, some situations cannot

Piping ConceptsPipelines are the oldest form of interprocess communication in Unix, and we refer to a data flow from one process to another as a "pipe", the essence of which is a fixed-size kernel buffer ;such as: PS aux | grep httpd | awk ' {print $

(Kernel 2.4.37)OneWhen we open a file, we need to get the file descriptor (previously said is the file array subscript), usually through the function open to complete, this system call in the header file declaration definition, we look at the

http://blog.chinaunix.net/space.php?uid=12567959&do=blog&id=161001 Open System call The open () system calls a service routine that is a sys_open () function that receives the path name filename of the file to be opened, flags for the access mode,

1. Concept:Asynchronous notification mechanism: Once the device is ready, the application is actively notified so that the application does not need to query the device state at all, and is a "signal-driven asynchronous I/O". The signal is a

1. Open File (Man 2 open View)int open (const char *pathname, int flags); //pathname file name (path); Flags open mode, O_rdonly, O_wronly, O_RDWRint open (const char *pathname, int flags, mode_t mode);This function is typically used to create new

Sometimes accidentally opening the same program two times will cause unexpected errors, the following describes a method to prevent this situation, the test is available.Add the following code to the program1#include 2#include 3#include 4#include

Consider the following Python code fragment. Do something with the data in the file, and then save the results back to the file: Copy Code code as follows: with open (filename) as F: input = F.read () Output = do_something

This article introduces how to use and pay attention to linux File I/O. If you need it, please refer to it. In Linux, most file I/O only uses five functions: open, read, write, lseek, and close. The functions involved in this topic are called I/O

What are the serial Programming Problems in linux ??? -- Linux general technology-Linux programming and kernel information. The following is a detailed description. In recent days, I learned serial programming and wrote code according to the

This article describes how to print python logs and write concurrent implementation code. generally, logging logs are used for printing. However, logging is thread-safe and many processes are introduced. some file locks are introduced, configure

Non-blocking I/Ononblocking I/O is not blocking I/O, that is, I am requesting an I/O operation, and if the I/O operation does not block when it is not completed, it returns an error code immediately.Specifies that the file descriptor is a