std::filesystem::create_directory, std::filesystem::create_directories

Defined in header `<filesystem>`
bool create_directory( const std::filesystem::path& p ); bool create_directory( const std::filesystem::path& p, std::error_code& ec );	(1)	(since C++17)
bool create_directory( const std::filesystem::path& p, const std::filesystem::path& existing_p ); bool create_directory( const std::filesystem::path& p, const std::filesystem::path& existing_p, std::error_code& ec );	(2)	(since C++17)
bool create_directories( const std::filesystem::path& p ); bool create_directories( const std::filesystem::path& p, std::error_code& ec );	(3)	(since C++17)

1) Creates the directory p as if by POSIX mkdir() with a second argument of static_cast<int>(std::filesystem::perms::all) (the parent directory must already exist). If p already exists and is already a directory, the function does nothing (this condition is not treated as an error).

2) Same as (1), except that the attributes of the new directory are copied from existing_p (which must be a directory that exists). It is OS-dependent which attributes are copied: on POSIX systems, the attributes are copied as if by

stat(existing_p.c_str(), &attributes_stat)
mkdir(p.c_str(), attributes_stat.st_mode)

On Windows OS, the attributes are copied as if by

CreateDirectoryExW(existing_p.c_str(), p.c_str(), 0)

3) Executes (1) for every element of p that does not already exist.

The non-throwing overloads return false if any error occurs.

Parameters

p	-	the path to the new directory to create
existing_p	-	the path to a directory to copy the attributes from
ec	-	out-parameter for error reporting in the non-throwing overload

Return value

1,2) true if directory creation is successful, false otherwise.

Exceptions

1,3) The overload that does not take a std::error_code& parameter throws filesystem_error on underlying OS API errors, constructed with p as the first argument and the OS error code as the error code argument. std::bad_alloc may be thrown if memory allocation fails. The overload taking a std::error_code& parameter sets it to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur. This overload has

noexcept specification:

noexcept

2) The overload that does not take a std::error_code& parameter throws filesystem_error on underlying OS API errors, constructed with p as the first argument, existing_p as the second argument, and the OS error code as the error code argument. std::bad_alloc may be thrown if memory allocation fails. The overload taking a std::error_code& parameter sets it to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur. This overload has

noexcept specification:

noexcept

Notes

The attribute-preserving overload (2) is implicitly invoked by copy() when recursively copying directories. Its equivalent in boost.filesystem is copy_directory (with argument order reversed)

Example

Run this code

#include <iostream>
#include <fstream>
#include <cstdlib>
#include <filesystem>
namespace fs = std::filesystem;
 
int main()
{
    fs::create_directories("sandbox/1/2/a");
    fs::create_directory("sandbox/1/2/b");
    fs::permissions("sandbox/1/2/b", fs::perms::remove_perms | fs::perms::others_all);
    fs::create_directory("sandbox/1/2/c", "sandbox/1/2/b");
    std::system("ls -l sandbox/1/2");
    fs::remove_all("sandbox");
}

Possible output:

drwxr-xr-x 2 user group 4096 Apr 15 09:33 a
drwxr-x--- 2 user group 4096 Apr 15 09:33 b
drwxr-x--- 2 user group 4096 Apr 15 09:33 c

Language
Standard library headers
Concepts
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)
Filesystem library (C++17)
Technical Specifications

create_symlinkcreate_directory_symlink (C++17)(C++17)	creates a symbolic link (function)
copy (C++17)	copies files or directories (function)
perms (C++17)	identifies file system permissions (enum)