#include <stdio.h>
    #include <direct.h>
    #include <io.h>
    #include <sys/stat.h>
    #include <sys/types.h>

    #define R_OK 4
    #define W_OK 2
    #define X_OK 1
    #define F_OK 0

    #else
    #include <unistd.h>
    #include <sys/stat.h>
    #include <sys/types.h>
    #endif
    namespace futil{
        /*
        * delete a name and possibly the file it refers to
        * On success, zero is returned. 
        * On error, -1 is returned, and errno is set appropriately.
        * _unlink
        * _wunlink
        * _tunlink
         */
        int unlink(const char *pathname){
            assert(pathname);
            if(pathname)
                return ::unlink(pathname);
            else
                return -1;
        }
        
        /*
        * create a temporary file
        * The tmpfile() function returns a stream descriptor, 
        * or NULL if a unique filename cannot be generated or 
        * the unique file cannot be opened. In the latter case,
        * errno is set to indicate the error.
         */
        FILE *tmpfile(void){
            return ::tmpfile();
        }
        
        /*
        * make a directory
        * Upon successful completion, mkdir() shall return 0. Otherwise, 
        * -1 shall be returned, no directory shall be created, 
        * and errno shall be set to indicate the error.
        * _tmkdir
        * _mkdir
        * _wmkdir
         */
        int mkdir(const char *path){
            assert(path);
            if(path)
                return ::mkdir(path);
            else
                return -1;
        }
        
        /*
        * delete a directory
        * On success, zero is returned. On error, -1 is returned, 
        * and errno is set appropriately.
         */
        int rmdir(const char *pathname){
            assert(pathname);
            if(pathname)
                return ::rmdir(pathname);
            else
                return -1;		
        }
        
        /*
        * change working directory
        * Upon successful completion, 0 shall be returned. 
        * Otherwise, -1 shall be returned, the current working directory
        * shall remain unchanged, and errno shall be set to indicate the error.
         */
        int chdir(const char *pathname){
            assert(pathname);
            if(pathname)
                return ::chdir(pathname);
            else
                return -1;	
        }
        
        /*
        * check real user's permissions for a file
        * On success (all requested permissions granted), zero is returned. 
        * On error (at least one bit in mode asked for a permission that is denied, 
        * or some other error occurred), -1 is returned, and errno is set appropriately.
        * _taccess		
        * _access	
        * _waccess
         */
        int access(const char *pathname, int mode){
            assert(pathname);
            if(pathname)
                return ::access(pathname,mode);
            else
                return -1;
        }

        inline bool filexist(const char* pathname){
            if(pathname)
                return !access(pathname,F_OK);
            else
                return false;
        }
        inline bool filereadable(const char* pathname){
            if(pathname)
                return !access(pathname,R_OK);
            else
                return false;
        }
        inline bool filewritable(const char* pathname){
            if(pathname)
                return !access(pathname,W_OK);
            else
                return false;
        }
        
        /*
        * change the name or location of a file
        * On success, zero is returned. On error, 
        * -1 is returned, and errno is set appropriately.
         */
        int rename(const char *oldpath, const char *newpath){
            assert(oldpath);
            assert(newpath);
            if(oldpath && newpath)
                return ::rename(oldpath,newpath);
            else
                return -1;
        }
        
        /*
        * stat, fstat, lstat - get file status
        * On success, zero is returned. On error, -1 is returned, 
        * and errno is set appropriately.
         */
        int stat2(const char *path, struct stat *buf){
            assert(path);
            assert(buf);
            if(path && buf)
                return ::stat(path,buf);
            else
                return -1;
        }
        
        inline bool filesize(const char* path,off_t* size){
            assert(size);
            struct stat stat_;
            if(size && !stat2(path,&stat_)){
                *size = stat_.st_size;
                return true;
            }else{
                return false;
            }
        }
    }