filesystem path string method returning mixed \ and /

Question

I have a C++ program where I use recursive iterator to go through folder that I provide as an argument to program.

Problem is that when I call .string on paths I get I get mixed \ and / in the path. Using .generic_string fixes this problem, but I wonder if this is a bug in VS2019 or allowed behavior.

To give some examples: I give a/b as input to my program.

When I iterate over all the files and print them using .string I get

a/b\c\bla.txt

a/b\d\lol.txt

and when I use .generic_string I get

a/b/c/bla.txt

a/b/d/lol.txt

Although windows supports either / or \ in most file operations I expect this is a bug in the implementation from microsoft. — drescherjm, Sep 16 '19 at 12:58
Use Windows sensibilities and pass `a\b` to your program. It otherwise doesn't matter at all, the OS handles either. — Hans Passant, Sep 16 '19 at 12:59
it's broken like this since MS-DOS, not using the normal slash... causing all this pain decades later... — Ped7g, Sep 16 '19 at 13:23

Ted Lyngmo · Answer 1 · 2019-09-16T16:49:29.177

Make sure that you convert the argument given by the user to an absolute path before using it with the directory iterator, otherwise, it'll display whatever the user supplied.

Example:

#include <filesystem>
#include <iostream>
#include <string_view>
#include <vector>

namespace fs = std::filesystem;

int ftw(const fs::path& p) {
    // give an absolute path to the iterator
    for (const auto& f : fs::recursive_directory_iterator(fs::absolute(p))) {
        std::cout << f.path().string() << "\n";
    }
    return 0;
}

int cppmain(const std::string_view program, std::vector<std::string_view> args) {
    for (const auto& arg : args)
        ftw(arg);
    return 0;
}

int main(int argc, char* argv[]) {
    return cppmain(argv[0], { argv + 1, argv + argc });
}

filesystem path string method returning mixed \ and /

1 Answers1