Article directory 0. Preface 1. C file interface file open file writing 2. System file interface open & amp; & amp; write & amp; & amp; close return value of open This chapter gitee code repository: file descriptor 0. Preface Knowledge of basic principles: File = content + attributes Files are divided into: Opened files […]
Tag: descriptor
Device driver letter Bind file descriptor
K1.c #include <linux/init.h> #include <linux/module.h> #include <linux/io.h> #include <linux/fs.h> #include <linux/types.h> #include <linux/gpio.h> #include <linux/cdev.h> #include <linux/device.h> #include “head.h” char kbuf[128] = {}; //Define three pointers pointing to mapped virtual memory unsigned int *vir_rcc; unsigned int *vir_moder_led1; unsigned int *vir_odr_led1; unsigned int *vir_moder_led2; unsigned int *vir_odr_led2; unsigned int *vir_moder_led3; unsigned int *vir_odr_led3; struct cdev *cdev; […]
What is the maximum number of file descriptors that Linux can open?
What is the maximum number of file descriptors that Linux can open? In daily development, operating on files is a very common thing. So do you have a question, how many files can I open at most? In the Linux system, when a program opens a file, the kernel will return the corresponding file descriptor […]
Redsocks traffic forwarding combined with iptables traffic transparent transmission under Linux appears socket: Too many open files and connect: Bad file descriptor
Under Linux, redsocks traffic forwarding combined with iptables traffic transparent transmission appears socket: Too many open files and connect: Bad file descriptor. Oct 8 18:59:34 localhost redsocks[26193]: connect: Bad file descriptor Oct 8 18:59:34 localhost redsocks[26193]: [192.168.10.10:53318->124.225.191.19:443]: red_connect_relay: Bad file descriptor Oct 8 18:59:34 localhost redsocks[26193]: [192.168.10.10:53318->124.225.191.19:443]: dropping client (R/W), relay (R/W), idle 0.000234s Oct […]
[Linux] File descriptors and redirection
File descriptor When the system interface open is called, a number of type int will be returned. This number is the file descriptor. Here we use fd to receive it. We Let’s take a look at the value of fd. As you can see, the value printed here is 3, so what is the origin […]
USB driver development 9 device descriptor
We have previously analyzed the endpoint descriptor, interface descriptor (each interface corresponds to a function and is equipped with a corresponding driver), configuration descriptor, and finally how the device includes these descriptors. First of all, remember that in the USB world, the device is greater than the configuration, and the configuration is greater than the […]
pcl–Section 6 3D feature descriptor
Feature Descriptor Feature Descriptor It is a unique identity authentication for each feature point Feature points of the same space point at different viewing angles have highly similar descriptors. The descriptors of different feature points should be as different as possible Usually the descriptor is a vector of fixed length Descriptors can be divided into […]
[Linux] File descriptors and redirection
File descriptors and redirections File reading and writing operations in C language the code How to open a file in open system System read and write file operations file descriptor file redirection How to understand file buffer File reading and writing operations in C language file writing fputs int fputs(const char *s, FILE *stream); s: […]
Linux system –makefile, gdb and file descriptor
Table of Contents 1 makefile 1.1 Basic rules of makefile 1.2 Makefile working principle 1.3 Variables in makefile 1.4 makefile function 1.5 Makefile cleaning operations 2 gdb debugging 2.1 Introduction to gdb 2.2 Generate debug information 2.3 start gdb 2.4 Display source code 3 file I/O 3.1 Workflow of C library IO function 3.2 Relationship […]
Sift: (Step 4) Construct descriptors for keypoints
Previous step: sift: (third step) give direction to key points_zzz_zzzz_’s Blog-CSDN Blog I think the hardest thing to understand is this fourth step. It seems simple, but if you look into it carefully, you still need to think about it carefully. Let me talk about Purpose first: through the previous three steps, we have found […]