mkdir Windows vs Linux

Question

I have a problem while porting a Linux tool to Windows. I am using MinGW on a Windows system. I have a class which handles all the in/output and within is this line:

mkdir(strPath.c_str(), 0777); // works on Linux but not on Windows and when it is changed to
_mkdir(strPath.c_str()); // it works on Windows but not on Linux

Any ideas what I can do, so that it works on both systems?

Solution 1

#if defined(_WIN32)
_mkdir(strPath.c_str());
#else 
mkdir(strPath.c_str(), 0777); // notice that 777 is different than 0777
#endif

Solution 2

You should be able to use conditional compilation to use the version that applies to the OS you are compiling for.

Also, are you really sure you want to set the flags to 777 (as in wide open, please deposit your virus here)?

Solution 3

You can conditionally compile with some preprocessor directives, a pretty complete list of which you can find here: C/C++ Compiler Predefined Macros

#if defined(_WIN32)
    _mkdir(strPath.c_str());
#elif defined(__linux__)
    mkdir(strPath.c_str(), 0777);
// #else more?
#endif

Comments

[wkl]

@EricJ. - _WIN32 is defined in 64-bit windows as well.

[heroddaji]

"_WIN32 - Defined for applications for Win32 and Win64". (ref: msdn.microsoft.com/en-us/library/b0084kay.aspx) Therefore the check for _WIN64 is not necessary here.

[gcochard]

For reference, that's a great thing to know. Short circuit evaluation makes it moot in this case though.

[jw013]

Shouldn't that be #if defined(_WIN32) || defined(_WIN64) to be valid? There's no such thing as #ifdef foo || bar - it's not valid preprocessor syntax as far as I know.

[gcochard]

@jw013 #ifdef is valid in both gnu c++ and the visual studio compilers. See gcc.gnu.org/onlinedocs/cpp/Ifdef.html, msdn.microsoft.com/en-us/library/t22e924w(v=vs.80).aspx, and stackoverflow.com/a/3803108/1355166 for more info.

[jw013]

@Greg You misunderstood. #ifdef constant_name is valid. #ifdef foo || bar is not. #ifdef doesn't take expressions. What compiler do you use that accepts such syntax?

[gcochard]

@jw013 I would say it's valid in visual studio, but now that I'm thinking about it, you're probably right. I will edit the answer with this in mind.

[Agostino]

_mkdir is included with direct.h in Visual Studio, and does not exist in GCC. You may want to add #ifdef _MSC_VER #include <direct.h> #endif

[Jon]

Live dangerously! ;)