getdfree.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

#include <precomp.h>
#include <ctype.h>
#include <direct.h>


/*
 * @implemented
 */
unsigned int _getdiskfree(unsigned int _drive, struct _diskfree_t* _diskspace)
{
    char RootPathName[10];

    RootPathName[0] = toupper(_drive +'@');
    RootPathName[1] = ':';
    RootPathName[2] = '\\';
    RootPathName[3] = 0;
    if (_diskspace == NULL)
        return 0;
    if (!GetDiskFreeSpaceA(RootPathName,(LPDWORD)&_diskspace->sectors_per_cluster,(LPDWORD)&_diskspace->bytes_per_sector,
            (LPDWORD )&_diskspace->avail_clusters,(LPDWORD )&_diskspace->total_clusters))
        return 0;
    return _diskspace->avail_clusters;
}