Question

I am writing a small class which can create/remove/rename/search for files and directories on the PC.

I successfully wrote the class and run on Linux.

When I was trying to run the same Class Code in MinGW, it was giving an error.
I could narrow down to:
mkdir function in Linux, Cygwin has 2 Arguments (directory name , mode permissions)
but in MinGW has only one argument(directory name).

My query is : a) What is the best way to make the code work on both OSs. b) Though I never used, I heard Preprocessor directives can be put like #ifdefined …..#endif ..or some thing of that sort c) Is using Preprocessor directives a good programming practice. As I learnt, preprocessor directives should be used minimally.

Could some one help me in this:

Here is my Code which works on Linux and Cygwin:

#include "BioDatabase.h"
#include <dirent.h>
#include <sys/stat.h>
#include <stdio.h>
#include <unistd.h>


BioDatabase::BioDatabase() {
   string s = getcwd(NULL,0);
   changeDirectory(s,"*");
}

BioDatabase::BioDatabase(string directoryName, string extension)
{
   changeDirectory(directoryName, extension);
}

bool BioDatabase::createDirectory(string st)
{
     if( mkdir(st.c_str(),0755) == -1)
    {
       cerr <<endl<<"BOSERR-BioDatabase, createDirectory: Path or file function not found or Permission denied\n\n";
       return false;
    }
    flag =1;
    return true;
}

Answer 1

You could code something like

 #if _POSIX_C_SOURCE
     if( mkdir(st.c_str()) == -1)
 #else
     if ((mkdir(st.c_str(),0755) == -1)
 #endif

See also feature_test_macros(7) man page.