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      std::filesystem::path::extension

      From cppreference.com
      <cpp‎ |filesystem‎ |path
       
       
      Filesystem library
      Classes
      Functions
      File types
       
      std::filesystem::path
      Member types
      Member constants
      Member functions
      Path decomposition
      Non-member functions
      (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)
      Helper classes
       
      path extension()const;
      (since C++17)

      Returns the extension of the filename component of the generic-format view of*this.

      If thefilename() component of the generic-format path contains a period (.), and is not one of the special filesystem elementsdot ordot-dot, then theextension is the substring beginning at the rightmost period (including the period) and until the end of the pathname.

      If the first character in the filename is a period, that period is ignored (a filename like ".profile" is not treated as an extension).

      If the pathname is either. or.., or iffilename() does not contain the'.' character, then empty path is returned.

      Additional behavior may be defined by the implementations for file systems which append additional elements (such as alternate data streams or partitioned dataset names) to extensions.

      Contents

      [edit]Parameters

      (none)

      [edit]Return value

      The extension of the current pathname or an empty path if there's no extension.

      [edit]Exceptions

      May throw implementation-defined exceptions.

      [edit]Notes

      The extension as returned by this function includes a period to make it possible to distinguish the file that ends with a period (function returns".") from a file with no extension (function returns"").

      On a non-POSIX system, it is possible thatp.stem()+ p.extension()!= p.filename() even though generic-format versions are the same.

      [edit]Example

      Run this code
      #include <filesystem>#include <iostream>namespace fs= std::filesystem; int main(){std::cout<< fs::path("/foo/bar.txt").extension()<<'\n'<< fs::path("/foo/bar.").extension()<<'\n'<< fs::path("/foo/bar").extension()<<'\n'<< fs::path("/foo/bar.txt/bar.cc").extension()<<'\n'<< fs::path("/foo/bar.txt/bar.").extension()<<'\n'<< fs::path("/foo/bar.txt/bar").extension()<<'\n'<< fs::path("/foo/.").extension()<<'\n'<< fs::path("/foo/..").extension()<<'\n'<< fs::path("/foo/.hidden").extension()<<'\n'<< fs::path("/foo/..bar").extension()<<'\n';}

      Output:

      ".txt""."""".cc""."""""""""".bar"

      [edit]See also

      returns the filename path component
      (public member function)[edit]
      returns the stem path component (filename without the final extension)
      (public member function)[edit]
      replaces the extension
      (public member function)[edit]
      checks if the corresponding path element is not empty
      (public member function)
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/filesystem/path/extension&oldid=158018"

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