Handling symbolic links (symlinks) in a directory can be important depending on whether you want to follow them or treat them as distinct entries. The std::filesystem::directory_iterator provides methods to check if an entry is a symlink.
Here’s how to identify and handle symbolic links:
#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main() {
fs::directory_iterator start{R"(c:\test)"};
fs::directory_iterator end{};
for (auto iter{start}; iter != end; ++iter) {
std::cout << iter->path().string();
if (iter->is_symlink()) {
std::cout << " (Symbolic Link)";
}
std::cout << '\n';
}
}c:\test\file1.txt
c:\test\symlink (Symbolic Link)
c:\test\directoryFollowing Symbolic Links:
If you want to follow symbolic links and access the target they point to, you can use std::filesystem::read_symlink():
#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main() {
fs::directory_iterator start{R"(c:\test)"};
fs::directory_iterator end{};
for (auto iter{start}; iter != end; ++iter) {
std::cout << iter->path().string();
if (iter->is_symlink()) {
auto target = fs::read_symlink(iter->path());
std::cout << " -> " << target.string();
}
std::cout << '\n';
}
}c:\test\file1.txt
c:\test\symlink -> c:\actual\path\to\file
c:\test\directoryKey Considerations:
- Security: Be cautious when following symlinks as they can point to unexpected locations, potentially leading to security issues.
- Recursion: When using
std::filesystem::recursive_directory_iterator, symlinks can cause infinite loops if they point back to an ancestor directory. Handle this by tracking visited directories or limiting recursion depth.
Ignoring Symbolic Links:
If you prefer to ignore symlinks, simply skip them in your iteration:
#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main() {
fs::directory_iterator start{R"(c:\test)"};
fs::directory_iterator end{};
for (auto iter{start}; iter != end; ++iter) {
if (iter->is_symlink()) {
continue;
}
std::cout << iter->path().string() << '\n';
}
}By understanding how to handle symbolic links, you can decide whether to follow them, log their targets, or ignore them based on your application’s needs.
Answers to questions are automatically generated and may not have been reviewed.
Directory Iterators
An introduction to iterating through the file system, using directory iterators and recursive directory iterators
