GetDiskFreeSpace

Can someone help me out with the GetDiskFreeSpace API?

Here is what i have and i'm getting values that don't seem correct.

Code:

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unsigned long *lpSectorsPerCluster;
        unsigned long *lpBytesPerSector;
        unsigned long *lpNumberOfFreeClusters;
        unsigned long *lpTotalNumberOfClusters;
       
        GetDiskFreeSpace("C:", lpSectorsPerCluster, lpBytesPerSector, lpNumberOfFreeClusters, lpTotalNumberOfClusters);
        cout << ((*lpTotalNumberOfClusters / 100) * (*lpSectorsPerCluster / 100) * (*lpBytesPerSector / 100))<< " Bytes Total" << endl;
        cout << ((*lpNumberOfFreeClusters / 100) * (*lpSectorsPerCluster / 100) * (*lpBytesPerSector / 100)) << " Bytes Free" << endl;

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thx in advance for any help

Quote:

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Originally posted by noble
Can someone help me out with the GetDiskFreeSpace API?

Here is what i have and i'm getting values that don't seem correct.

Code:

---

unsigned long lpSectorsPerCluster;
        unsigned long lpBytesPerSector;
        unsigned long lpNumberOfFreeClusters;
        unsigned long lpTotalNumberOfClusters;
       
        GetDiskFreeSpace("C:", &lpSectorsPerCluster, &lpBytesPerSector, &lpNumberOfFreeClusters, &lpTotalNumberOfClusters);
        cout << ((*lpTotalNumberOfClusters / 100) * (*lpSectorsPerCluster / 100) * (*lpBytesPerSector / 100))<< " Bytes Total" << endl;
        cout << ((*lpNumberOfFreeClusters / 100) * (*lpSectorsPerCluster / 100) * (*lpBytesPerSector / 100)) << " Bytes Free" << endl;

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The idea is that you pass a pointer to your variables, not pass the VALUE from a pointer variable you have...see my subtle changes in the variable declaration...

Argh gotta go...change the printing to avoid the dereference...

still seem off by a little.....

Code:

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unsigned long lpSectorsPerCluster;
                unsigned long lpBytesPerSector;
                unsigned long lpNumberOfFreeClusters;
                unsigned long lpTotalNumberOfClusters;
               
                GetDiskFreeSpace(szDriveLetter, &lpSectorsPerCluster, &lpBytesPerSector, &lpNumberOfFreeClusters, &lpTotalNumberOfClusters);
                cout << ((lpTotalNumberOfClusters / 100) * (lpSectorsPerCluster / 100) * (lpBytesPerSector / 100)) << " Bytes Total" << endl;
                cout << ((lpNumberOfFreeClusters / 100) * (lpSectorsPerCluster / 100) * (lpBytesPerSector / 100)) << " Bytes Free" << endl;

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GetDiskFreeSpaceEx will be simpler to use. It was designed to replace GetDiskFreeSpace.

But if you want to use GetDiskFreeSpace, why do you divide all numbers by 100?

oops, i copied some code from a previous project and forgot
to take out the dividing by 100. Still doesn't give me a correct
reading on the free space....

I'm not using GetDiskFreeSpaceEx because I need to know the
sectors and such.

Thanks again

Noble, I just said it was off - I'd written the core part of the reply before I got dragged off to do my presentation (on a course at the moment).

If you didn't notice the fact that I said you needed to follow the changes in the variables through to remove the dereferencing :p

Anyway, have you tried looking up GetDiskSpaceFree on MSDN?

thx parksie for your help, i realized what I did wrong before and
fixed it