Get a file name from a path

Question

What is the simplest way to get the file name that from a path?

string filename = "C:\\MyDirectory\\MyFile.bat" 

In this example, I should get "MyFile". without extension.

Answer 1

The task is fairly simple as the base filename is just the part of the string starting at the last delimeter for folders:

std::string base_filename = path.substr(path.find_last_of("/\\") + 1) 

If the extension is to be removed as well the only thing to do is find the last . and take a substr to this point

std::string::size_type const p(base_filename.find_last_of('.')); std::string file_without_extension = base_filename.substr(0, p); 

Perhaps there should be a check to cope with files solely consisting of extensions (ie .bashrc...)

If you split this up into seperate functions you're flexible to reuse the single tasks:

template<class T> T base_name(T const & path, T const & delims = "/\\") {   return path.substr(path.find_last_of(delims) + 1); } template<class T> T remove_extension(T const & filename) {   typename T::size_type const p(filename.find_last_of('.'));   return p > 0 && p != T::npos ? filename.substr(0, p) : filename; } 

The code is templated to be able to use it with different std::basic_string instances (i.e. std::string & std::wstring...)

The downside of the templation is the requirement to specify the template parameter if a const char * is passed to the functions.

So you could either:

A) Use only std::string instead of templating the code

std::string base_name(std::string const & path) {   return path.substr(path.find_last_of("/\\") + 1); } 

B) Provide wrapping function using std::string (as intermediates which will likely be inlined / optimized away)

inline std::string string_base_name(std::string const & path) {   return base_name(path); } 

C) Specify the template parameter when calling with const char *.

std::string base = base_name<std::string>("some/path/file.ext"); 

Result

std::string filepath = "C:\\MyDirectory\\MyFile.bat"; std::cout << remove_extension(base_name(filepath)) << std::endl; 

Prints

MyFile 

Answer 2

A possible solution:

string filename = "C:\\MyDirectory\\MyFile.bat";  // Remove directory if present. // Do this before extension removal incase directory has a period character. const size_t last_slash_idx = filename.find_last_of("\\/"); if (std::string::npos != last_slash_idx) {     filename.erase(0, last_slash_idx + 1); }  // Remove extension if present. const size_t period_idx = filename.rfind('.'); if (std::string::npos != period_idx) {     filename.erase(period_idx); }