c++ 17 filesystem::remove_all 带通配符路径

Question

我想删除所有文件、文件夹和子文件夹，但不删除父文件夹。
所以我尝试使用带有通配符的 filesystem::remove_all ，但这似乎不起作用。

filesystem::removeall("pathtofolder/*");

也不异常(exception)，但它不会删除任何内容。
是否不允许使用通配符？
我真的需要调用 pathtofolder 中的每个文件和文件夹吗？ removeall方法？

Answer 1

Are wildcards are not allowed?

不支持 globbing (通配符)在 std::filesystem::remove_all :

Deletes the contents of p (if it is a directory) and the contents of all its subdirectories, recursively, then deletes p itself as if by repeatedly applying the POSIX remove. Symlinks are not followed (symlink is removed, not its target)

Do I really need to call for each file and folder inside of pathtofolder the removeall method?

是的，因此您的电话应该是这样的:

#include <cstdint>
#include <exception>
#include <filesystem>
#include <iostream>
#include <system_error>

int main() {
    try {
        std::uintmax_t count = 0;

        // loop over all the "directory_entry"'s in "pathtofolder":
        for(auto& de : std::filesystem::directory_iterator("pathtofolder")) {
            // returns the number of deleted entities since c++17:
            count += std::filesystem::remove_all(de.path());
        }
        std::cout << "deleted " << count << " files and directories\n";

    } catch(const std::exception& ex) {
        // The overloads that does not take a std::error_code& parameter throws
        // filesystem_error on underlying OS API errors, constructed with p as
        // the first path argument and the OS error code as the error code
        // argument.

        // directory_iterator:  throws if the directory doesn't exist
        // remove_all:          does NOT throw if the path doesn't exist

        std::cerr << ex.what() << std::endl;
    }
}

请注意，如果 de.path()不存在，它不是操作系统 API 错误，也不会 throw一个异常(exception)。它将返回 0删除的文件和目录(或 C++17 之前的 false)。
然而， directory_iterator()会抛出 filesystem_error如果 pathtofolder不存在。