Introduction: Are you still confused about the order of operations in complex expressions? Are you encountering bugs in your programs due to incorrect operator precedence? Mastering the operator precedence in C not only allows you to write cleaner code but also helps avoid 90% of logical errors! This article uses a single diagram to thoroughly … Read more
1. Introduction to Application Scenarios In industrial control and teaching practice, PLC light control is a fundamental and typical case. This article focuses on the Siemens S7-200 SMART PLC to implement the alternating flashing function of eight LED lights in two groups, suitable for scenarios such as indicator light control and running light simulation. 2. … Read more
The key to whether a program is easy to debug lies in the completeness of the debugging information. This article provides a brief introduction to what DWARF debugging information is based on this premise. What is DWARF Debugging With Attributed Record Formats is a debugging information format used by many compilers, which allows for easy … Read more
We know that ptrace frequently issues PTRACE_GETREGS and PTRACE_SETREGS commands, modifying the PC register, allowing the process to be controlled by gdb and execute related commands at the trace point. This article uses a simple program to demonstrate basic debugging tasks using gdb. What to Debug Based on the understanding of ptrace, we can summarize … Read more
“Assembly Language”, 3rd Edition by Wang Shuang Chapter 13 int Instruction (Page 262) Experiment 13 Writing and Applying Interrupt Routines ———————————— Note: This is the code example and analysis for Experiment 13Question 1. ———————————– (1) Write and install the int 7cH interrupt routine, which displays a null-terminated string. The interrupt routine is installed at 0:200. … Read more
gdb is a commonly used debugging tool in the workplace. A friend suggested that I introduce the usage of gdb, and after some thought, I decided to organize my own experiences with gdb into a series. This serves both to reinforce my foundational knowledge and to share some of my experiences and techniques. References All … Read more
GDB uses the ptrace system call to implement its functionality. This article provides a brief overview of ptrace. Ptrace The ptrace system call /* kernel/ptrace.c */ #define __NR_ptrace 117 __SYSCALL(__NR_ptrace, sys_ptrace) When using ptrace, you need to include<span>/sys/ptrace.h</span>. When calling the ptrace system call, you need to send requests based on different requests, which are … Read more
Hello everyone, I am Programmer Wan Feng. My learning website is: www.python-office.com, focusing on AI and Python automation for office tasks.[1] 1. Concepts and Principles During development, we often need to output JSON data in the terminal. However, the default JSON output is usually monochrome, making it difficult to quickly identify the data structure. Terminal … Read more
In addition to a large number of “special methods” that control object behavior, Python also provides a series of special attributes that describe the meta-information of modules, functions, instances, and classes. These attributes typically appear in the form of __name__, __doc__, __dict__, etc., and are the foundation for introspection, debugging, reflection, and even framework design. … Read more
I worry that when I mentionPCB test points, you might not know what I am talking about, so I specifically searched for a video screenshot on Bilibili to show you: If you have ever used a NOKIA phone, every time you open the back cover to change the battery, you seethose two rows of circular … Read more