Windows API Reference

CreateDirectory

The CreateDirectory function creates a new directory with the specified path. If the directory already exists, the function fails and returns FALSE.

Syntax

BOOL CreateDirectory(
  LPCTSTR lpPathName,
  LPSECURITY_ATTRIBUTES lpSecurityAttributes
);

Parameters

Parameter	Type and Description	Notes
lpPathName	LPCTSTR The path of the directory to be created. This string can be a name composed of characters that are valid for directory and file names. It can also be a Unicode (WCHAR) or an ANSI string.	Required. The maximum string size for a path is MAX_PATH, which is 260 characters. Use \\?\C:\verylongpath to specify a path longer than 260 characters.
lpSecurityAttributes	LPSECURITY_ATTRIBUTES A pointer to a SECURITY_ATTRIBUTES structure that specifies the security descriptor for the new directory. If this parameter is NULL, the directory gets a default security descriptor that is the same as the directory or process that created it.	Optional.

Return Value

Return Value	Description	Conditions
TRUE	The directory was created successfully.	Success.
FALSE	The directory was not created. To get extended error information, call GetLastError.	Failure.

Remarks

• If the lpSecurityAttributes parameter is NULL, the function uses the default security attributes.
• The function will fail if the specified path already exists. For scenarios where you want to create a directory if it doesn't exist, consider using CreateDirectoryEx with the CREATE_ALWAYS flag.
• The function creates intermediate directories as needed. For example, if lpPathName is "C:\NewDir\NewSubdir" and "C:\NewDir" does not exist, the function will create both directories.

Example

#include <windows.h>
#include <iostream>

int main() {
    const char* dirName = "C:\\MyNewDirectory";

    if (CreateDirectory(dirName, NULL)) {
        std::cout << "Directory '" << dirName << "' created successfully." << std::endl;
    } else {
        DWORD error = GetLastError();
        if (error == ERROR_ALREADY_EXISTS) {
            std::cout << "Directory '" << dirName << "' already exists." << std::endl;
        } else {
            std::cerr << "Failed to create directory. Error code: " << error << std::endl;
        }
    }

    return 0;
}