Can't remove an empty folder in C++

Question

I want to remove an empty folder using remove() in C++ on Windows 7 but I can't. I tried rmdir() instead of remove() then the folder got removed! Nevertheless, the reason why I don't use rmdir() is due to Android. In a library project for Android, I can't include "direct.h" header so can't use rmdir() , either. Unlike on Windows, the function remove() works well on Android. I don't understand why.

Anybody knows why this is happening?

Or any other functions which will work on both Windows and Android?

Answer 1

This is a pretty common problem when writing cross-platform programs.

Sometimes, a library can provide the abstraction you need. For example, Boost has a filesystem library that can enumerate files, manipulate directories, etc., on multiple platforms using the exact same code.

Also, there are usually symbols defined that allow you to detect which compiler is currently building your code. Even if there isn't one that does what you want, you can define your own.

Let's say you need to build your software for two different fictitional operating systems named FooOS and for BarOS. I'm going to invent two symbols, FOO_OS and BAR_OS . In my code, I can do something like this:

#ifdef FOO_OS
#include <foo_stuff.h>
#elseif BAR_OS
#include <bar_stuff.h>
#endif

void do_something()
{
#ifdef FOO_OS
    do_it_this_way();
#elseif BAR_OS
    do_it_that_way();
#endif
}

Now, we just need to either define FOO_OS or BAR_OS . This can be done through an IDE's project configuration or on the command line of the compiler. Use Google to find out about your particular situation, since you didn't include those details in your post.

There is a preprocessing step when you compile your code that makes a pass through the source, and applies these conditional statements. A following pass actually compiles the code. Here is some documentation about Visual Studio's preprocessor, for example.