How to get file size using C++?
Jun 01, 2024 pm 02:22 PMQuestion: How to get file size in C++? Answer: 1. Use the std::ifstream::tellg() member function to get the number of bytes read or written since opening the file stream; 2. Use std::filesystem::directory_iterator to traverse the files in the directory and Use std::ifstream::tellg() to calculate the number of bytes in each file and add them up to get the total size.
#How to get file size in C++?
In C++, you can use the std::ifstream
class to open and read files. This class contains std::ifstream::tellg()
member function which returns the number of bytes read or written since the file stream was opened. This can be used to get the size of the file.
Code example:
#include <iostream> #include <fstream> int main() { // 打開文件 std::ifstream file("myfile.txt"); // 獲取文件的大小 file.seekg(0, std::ios::end); int file_size = file.tellg(); // 打印文件大小 std::cout << "The file size is: " << file_size << " bytes" << std::endl; file.close(); return 0; }
Practical case:
The following is a method to obtain the total size of all files in a specific directory Example:
#include <iostream> #include <fstream> #include <filesystem> int main() { std::filesystem::path directory_path("my_directory"); // 遍歷目錄中的文件 int total_file_size = 0; for (const auto& entry : std::filesystem::directory_iterator(directory_path)) { if (entry.is_regular_file()) { // 打開文件 std::ifstream file(entry.path()); // 獲取文件大小并累加到總和 file.seekg(0, std::ios::end); total_file_size += file.tellg(); file.close(); } } // 打印總文件大小 std::cout << "The total size of all files in the directory is: " << total_file_size << " bytes" << std::endl; return 0; }
The above is the detailed content of How to get file size using C++?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Handling high DPI display in C can be achieved through the following steps: 1) Understand DPI and scaling, use the operating system API to obtain DPI information and adjust the graphics output; 2) Handle cross-platform compatibility, use cross-platform graphics libraries such as SDL or Qt; 3) Perform performance optimization, improve performance through cache, hardware acceleration, and dynamic adjustment of the details level; 4) Solve common problems, such as blurred text and interface elements are too small, and solve by correctly applying DPI scaling.

DMA in C refers to DirectMemoryAccess, a direct memory access technology, allowing hardware devices to directly transmit data to memory without CPU intervention. 1) DMA operation is highly dependent on hardware devices and drivers, and the implementation method varies from system to system. 2) Direct access to memory may bring security risks, and the correctness and security of the code must be ensured. 3) DMA can improve performance, but improper use may lead to degradation of system performance. Through practice and learning, we can master the skills of using DMA and maximize its effectiveness in scenarios such as high-speed data transmission and real-time signal processing.

ABI compatibility in C refers to whether binary code generated by different compilers or versions can be compatible without recompilation. 1. Function calling conventions, 2. Name modification, 3. Virtual function table layout, 4. Structure and class layout are the main aspects involved.

Using the chrono library in C can allow you to control time and time intervals more accurately. Let's explore the charm of this library. C's chrono library is part of the standard library, which provides a modern way to deal with time and time intervals. For programmers who have suffered from time.h and ctime, chrono is undoubtedly a boon. It not only improves the readability and maintainability of the code, but also provides higher accuracy and flexibility. Let's start with the basics. The chrono library mainly includes the following key components: std::chrono::system_clock: represents the system clock, used to obtain the current time. std::chron

C code optimization can be achieved through the following strategies: 1. Manually manage memory for optimization use; 2. Write code that complies with compiler optimization rules; 3. Select appropriate algorithms and data structures; 4. Use inline functions to reduce call overhead; 5. Apply template metaprogramming to optimize at compile time; 6. Avoid unnecessary copying, use moving semantics and reference parameters; 7. Use const correctly to help compiler optimization; 8. Select appropriate data structures, such as std::vector.

C performs well in real-time operating system (RTOS) programming, providing efficient execution efficiency and precise time management. 1) C Meet the needs of RTOS through direct operation of hardware resources and efficient memory management. 2) Using object-oriented features, C can design a flexible task scheduling system. 3) C supports efficient interrupt processing, but dynamic memory allocation and exception processing must be avoided to ensure real-time. 4) Template programming and inline functions help in performance optimization. 5) In practical applications, C can be used to implement an efficient logging system.

The main difference between Java and other programming languages ??is its cross-platform feature of "writing at once, running everywhere". 1. The syntax of Java is close to C, but it removes pointer operations that are prone to errors, making it suitable for large enterprise applications. 2. Compared with Python, Java has more advantages in performance and large-scale data processing. The cross-platform advantage of Java stems from the Java virtual machine (JVM), which can run the same bytecode on different platforms, simplifying development and deployment, but be careful to avoid using platform-specific APIs to maintain cross-platformity.

Reducing the use of global variables in C can be achieved by: 1. Using encapsulation and singleton patterns to hide data and limit instances; 2. Using dependency injection to pass dependencies; 3. Using local static variables to replace global shared data; 4. Reduce the dependence of global variables through namespace and modular organization of code.
