parent_path() with or without trailing slash
To remove the trailing separator from a path that is to a directory, so far this is working for me:
/**
* Creates lexically normal (removes extra path separators and dots) directory
* path without trailing path separator slash(es)
* @param dir_path - directory path to normalize
*/
void normalize_dir_path(boost::filesystem::path& dir_path) {
// @HACK - append non-existing file to path so that we may later resolve
// normalized directory path using parent_path()
dir_path /= "FILE.TXT";
// Remove unneeded dots and slashes
dir_path = dir_path.lexically_normal();
// Remove trailing slash from original path!
dir_path = dir_path.parent_path();
}
The above answer is similar to OP's original posted workaround (add '/'
) in combination with Wurmloch's comment about using lexically_normal()
. One advantage is that only the documented methods from boost::filesystem
are used. One possible disadvantage is that caller must be confident the input argument dir_path
is intended to be a directory and not a regular file.
Using the normalize_dir_path(...)
method to answer OP's question:
boost::filesystem::path filePath1 = "/home/user/";
normalize_dir_path(filePath1); // filePath1 is now "/home/user"
cout << filePath1.parent_path() << endl; // outputs "/home"
boost::filesystem::path filePath2 = "/home/user";
normalize_dir_path(filePath2); // filePath2 is now "/home/user"
cout << filePath2.parent_path() << endl; // outputs "/home"
boost::filesystem::path filePath3 = "/home/user/.";
normalize_dir_path(filePath3); // filePath3 is now "/home/user"
cout << filePath3.parent_path() << endl; // outputs "/home"
Update
Just realized that boost::filesystem::path::lexically_normal()
is only available on BOOST version >= 1_60_0. For earlier versions, there appears to be a deprecated function available by default boost::filesystem::path::normalize()
(as long as BOOST_FILESYSTEM_NO_DEPRECATED
is not defined). So, my current normalize directory path method is along the lines:
#include <boost/version.hpp>
void normalize_dir_path(boost::filesystem::path& dir_path) {
// @HACK - append non-existing file to path so that we may later resolve
// normalized directory path using parent_path()
dir_path /= "FILE.TXT";
// Remove unneeded dots and slashes
#if BOOST_VERSION >= 106000
dir_path = dir_path.lexically_normal();
#else
dir_path.normalize();
#endif
// Remove trailing slash from original path!
dir_path = dir_path.parent_path();
}
There is a (undocumented?) member function: path& path::remove_trailing_separator();
I tried this and it worked for me on Windows using boost 1.60.0
:
boost::filesystem::path filePath1 = "/home/user/";
cout << filePath1.parent_path() << endl; // outputs "/home/user"
cout << filePath1.remove_trailing_separator().parent_path() << endl; // outputs "/home"
boost::filesystem::path filePath2 = "/home/user";
cout << filePath2.parent_path() << endl; // outputs "/home"
cout << filePath2.remove_trailing_separator().parent_path() << endl; // outputs "/home"
Seems like it, although I would recommend doing a previous manipulation with the directory string
instead of calling twice to parent_path()
:
std::string directory = "/home/user"; // Try with "/home/user/" too, result is the same
while ((directory.back() == '/') || (directory.back() == '\\')))
directory.erase(directory.size()-1);
boost::filesystem::path filePath(directory);
std::cout << filePath.parent_path() << std::endl; // outputs "/home"
It is important to note that std::string::back()
is a C++11 feature. Should you need to compile with a previous version you will have to change the algorithm a bit.
You can use std::filesystem::canonical
with C++17:
namespace fs = std::filesystem;
fs::path tmp = "c:\\temp\\";
tmp = fs::canonical(tmp); // will remove slash
fs::path dir_name = tmp.filename(); // will get temp