Move a file that user chooses to another directory - c++

Question

I'm trying to make a program that moves a file (like file.txt) specified by the user to a directory that he also specifies. I tried using the move() function, however I don't quite understand it yet, so I tried with the rename() function and used this site's code as help.
I've worked with the rename() function and moved a file like this:
char oldDir[] = "C:\\Users\\MyName\\file.txt";
char newDir[] = "C:\\Users\\MyName\\New folder\\file.txt";
if (rename(oldDir, newDir) != 0)
perror("Error moving file");
else
cout << "File moved successfully";
And that worked perfectly, if I typed in the directory correctly. The thing is that I would like to tell the user to type in the directory of a file to move to another directory, so I tried this:
char oldDir[] = " ";
char newDir[] = " ";
cout << "Type file directory: "; cin >> oldDir;
cout << "Type file directory to move to: "; cin >> newDir;
if (rename(oldDir, newDir) != 0)
perror("Error moving file");
else
cout << "File moved successfully";
But, when typing in the console the oldDir path like: C:\\Users\\MyName\\file.txt, I always get the error:
Error moving file no such file or directory
It returns before I can even type the newDir path. Of course the file.txt is in C:\Users\MyName.
What could be the problem? I tried to remove the " " from the oldDir and newDir variables, but then I get another error:
incomplete type is not allowed
What am I doing wrong?

Answer 1

First off, don't double up on the slashes when typing them in at the command prompt at runtime, if that is what you are doing. Escaping slashes only applies to string literals in code, not runtime data.
That said, you are not allocating enough memory to hold the user's input. When initialized with " ", your oldDir[] and newDir[] arrays are each only 2 chars in size. When you drop the " ", the compiler no longer knows how large to make the array, since you are not telling it which size to use.
You need to handle the arrays more like this instead:
char oldDir[MAX_PATH] = "";
char newDir[MAX_PATH] = "";
std::cout << "Type file directory: ";
cin.getline(oldDir, MAX_PATH); // paths can contain spaces!
std::cout << "Type file directory to move to: ";
cin.getline(newDir, MAX_PATH); // paths can contain spaces!
if (rename(oldDir, newDir) != 0)
perror("Error moving file");
else
std::cout << "File moved successfully" << std::endl;
However, you really should be using std::string instead:
std::string oldDir, newDir;
std::cout << "Type file directory: ";
std::getline(cin, oldDir); // paths can contain spaces!
std::cout << "Type file directory to move to: ";
std::getline(cin, newDir); // paths can contain spaces!
if (rename(oldDir.c_str(), newDir.c_str()) != 0)
perror("Error moving file");
else
std::cout << "File moved successfully" << std::endl;
If you are using C++17 or later, consider using std::filesystem::rename() instead of ::rename():
#include <filesystem>
std::string oldDir, newDir;
std::cout << "Type file directory: ";
std::getline(cin, oldDir); // paths can contain spaces!
std::cout << "Type file directory to move to: ";
getline(cin, newDir); // paths can contain spaces!
std::error_code err;
std::filesystem::rename(oldDir, newDir, err);
if (err)
std::cerr << "Error moving file: " << err.message() << endl;
else
std::cout << "File moved successfully" << std::endl;