Portable and efficient file system access with <filesystem> library

Portable and efficient file system access with library

13 Oct 2023

One of the most common tasks in software development is handling file system operations such as creating, deleting, and manipulating files and directories. C++ provides the <filesystem> library as part of the Standard Template Library (STL) to provide portable and efficient file system access.

What is `<filesystem>`?

<filesystem> is a header file introduced in the C++17 standard. It provides a set of classes and functions to perform file system operations in a platform-independent manner. Before <filesystem>, developers relied on platform-specific code or third-party libraries to work with files and directories.

Basic File System Operations

Let’s take a look at some of the basic file system operations that <filesystem> provides:

Creating a Directory: To create a directory, you can use the std::filesystem::create_directory function. For example:
```
std::filesystem::create_directory("path/to/directory");
```
Creating a File: To create an empty file, you can use the std::ofstream class from the <fstream> header. For example:
```
std::ofstream file("path/to/file.txt");
```
Checking if a Path Exists: You can use the std::filesystem::exists function to check if a file or directory exists. For example:
```
if (std::filesystem::exists("path/to/file.txt")) {
    std::cout << "File exists!" << std::endl;
}
```

Iterating Through a Directory: The std::filesystem::directory_iterator class allows you to iterate through the contents of a directory. For example:

for (const auto& entry : std::filesystem::directory_iterator("path/to/directory")) {
    std::cout << entry.path() << std::endl;
}

Renaming or Moving a File: The std::filesystem::rename function can be used to rename or move a file. For example:
```
std::filesystem::rename("old_path/file.txt", "new_path/file.txt");
```

Compatibility and Portability

The <filesystem> library provides a consistent interface across different operating systems, making your code portable. It abstracts the differences in file system handling between Windows, macOS, and Linux, simplifying cross-platform development.

Efficiency

The <filesystem> library is designed to be efficient and performant. It aims to minimize unnecessary system calls and optimize file system operations. However, performance can vary depending on the underlying operating system and file system implementation.

Conclusion

The <filesystem> library in C++ provides a portable and efficient way to work with files and directories. It simplifies common file system operations and eliminates the need for platform-specific or third-party libraries. By adopting <filesystem>, you can write more maintainable and portable code across different operating systems.

Give it a try in your next project and enjoy the benefits of a standardized file system API!

References

cppreference.com - <filesystem> #cplusplus #filesystem

What is <filesystem>?