How can I copy a directory using Boost Filesystem

Question

How can I copy a directory using Boost Filesystem? I have tried boost::filesystem::copy_directory() but that only creates the target directory and does not copy the contents.

Answer 1

bool copyDir(     boost::filesystem::path const & source,     boost::filesystem::path const & destination ) {     namespace fs = boost::filesystem;     try     {         // Check whether the function call is valid         if(             !fs::exists(source) ||             !fs::is_directory(source)         )         {             std::cerr << "Source directory " << source.string()                 << " does not exist or is not a directory." << '\n'             ;             return false;         }         if(fs::exists(destination))         {             std::cerr << "Destination directory " << destination.string()                 << " already exists." << '\n'             ;             return false;         }         // Create the destination directory         if(!fs::create_directory(destination))         {             std::cerr << "Unable to create destination directory"                 << destination.string() << '\n'             ;             return false;         }     }     catch(fs::filesystem_error const & e)     {         std::cerr << e.what() << '\n';         return false;     }     // Iterate through the source directory     for(         fs::directory_iterator file(source);         file != fs::directory_iterator(); ++file     )     {         try         {             fs::path current(file->path());             if(fs::is_directory(current))             {                 // Found directory: Recursion                 if(                     !copyDir(                         current,                         destination / current.filename()                     )                 )                 {                     return false;                 }             }             else             {                 // Found file: Copy                 fs::copy_file(                     current,                     destination / current.filename()                 );             }         }         catch(fs::filesystem_error const & e)         {             std:: cerr << e.what() << '\n';         }     }     return true; } 

Usage:

copyDir(boost::filesystem::path("/home/nijansen/test"), boost::filesystem::path("/home/nijansen/test_copy")); (Unix)

copyDir(boost::filesystem::path("C:\\Users\\nijansen\\test"), boost::filesystem::path("C:\\Users\\nijansen\\test2")); (Windows)

As far as I see, the worst that can happen is that nothing happens, but I won't promise anything! Use at your own risk.

Please note that the directory you're copying to must not exist. If directories within the directory you are trying to copy can't be read (think rights management), they will be skipped, but the other ones should still be copied.

Update

Refactored the function respective to the comments. Furthermore the function now returns a success result. It will return false if the requirements for the given directories or any directory within the source directory are not met, but not if a single file could not be copied.

Answer 2

Since C++17 you don't need boost for this operation anymore as filesystem has been added to the standard.

Use std::filesystem::copy

#include <exception> #include <filesystem> namespace fs = std::filesystem;  int main() {     fs::path source = "path/to/source/folder";     fs::path target = "path/to/target/folder";      try {         fs::copy(source, target, fs::copy_options::recursive);     }     catch (std::exception& e) { // Not using fs::filesystem_error since std::bad_alloc can throw too.         // Handle exception or use error code overload of fs::copy.     } } 

See also std::filesystem::copy_options.