The Windows File Management 6

 

 

 

File Type, Size and Timestamp Program Example

 

The following program example demonstrates the use of file type, file size and timestamp functions.

 

 

Create a new empty Win32 console application project. Give a suitable project name and change the project location if needed.

Then, add the source file and give it a suitable name.

Next, add the following source code.

 

// FileWriteLastTime - Retrieves the last-write time and converts the time to a string

// Return value - TRUE if successful, FALSE otherwise

// hFile      - Valid file handle

// lpszString - Pointer to buffer to receive string

#include <windows.h>

#include <strsafe.h>

 

// A prototype that receives a function name, displaying

// system error code and its respective message

void DisplayErrorBox(LPTSTR lpszFunction);

 

BOOL GetLastWriteTime(HANDLE hFile, LPTSTR lpszString, DWORD dwSize)

{

    FILETIME ftCreate, ftAccess, ftWrite;

    SYSTEMTIME stUTC, stLocal;

    DWORD dwRet;

 

    // Retrieve the file times for the file.

    if (!GetFileTime(hFile, &ftCreate, &ftAccess, &ftWrite))

        return FALSE;

 

    // Convert the last-write time to local time.

    FileTimeToSystemTime(&ftWrite, &stUTC);

    SystemTimeToTzSpecificLocalTime(NULL, &stUTC, &stLocal);

 

    // Build a string showing the date and time.

    dwRet = StringCchPrintf(lpszString, dwSize,

        L%02d/%02d/%d  %02d:%02d,

        stLocal.wMonth, stLocal.wDay, stLocal.wYear,

        stLocal.wHour, stLocal.wMinute);

 

    if(S_OK == dwRet)

        return TRUE;

    else return FALSE;

}

 

int wmain(int argc, WCHAR *argv[])

{

    HANDLE hFile;

    WCHAR szBuf[MAX_PATH];

    DWORD dwFileType = 0;

    LARGE_INTEGER lpFileSize;

    BOOL bRetVal;

 

    if(argc != 2)

    {

        wprintf(LThis sample takes a file name as an argument\n);

        wprintf(L%s <file_name_to_check>\n, argv[0]);

        wprintf(L%s C:\\anothertestfile.doc\n, argv[0]);

        // Non-zero means error

        return 1;

    }

 

    hFile = CreateFile(argv[1], GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);

 

    if(hFile == INVALID_HANDLE_VALUE)

    {

        DisplayErrorBox(LCreateFile());

        return 1;

    }

    else

        wprintf(LCreateFile() is pretty fine!\n);

 

      dwFileType = GetFileType(hFile);

 

      switch(dwFileType)

      {

      case FILE_TYPE_CHAR: wprintf(L%s is a character file, typically an LPT device or a console.\n, argv[1]);

            break;

      case FILE_TYPE_DISK: wprintf(L%s is a disk file\n, argv[1]);

            break;

      case FILE_TYPE_PIPE: wprintf(L%s is a socket, a named pipe, or an anonymous pipe.\n, argv[1]);

            break;

      case FILE_TYPE_UNKNOWN: wprintf(L%s is unknown, or the function failed!\n, argv[1]);

            break;

      default:

            wprintf(L%s is unknown type!\n, argv[1]);

      }

 

      bRetVal = GetFileSizeEx(hFile, &lpFileSize);

 

      // TRUE

      if(bRetVal != 0)

      {

            wprintf(LGetFileSizeEx() looks fine!\n);

            wprintf(LFile size is %u bytes\n, lpFileSize.QuadPart);

      }

      else

            DisplayErrorBox(LGetFileSizeEx());

 

 

    if(GetLastWriteTime(hFile, szBuf, MAX_PATH))

        wprintf(LLast write time is: %s\n, szBuf);       

    if(CloseHandle(hFile) != 0)

        wprintf(LhFile handle was closed successfully!\n);

      else

            DisplayErrorBox(LCloseHandle());

 

      return 0;

}

 

void DisplayErrorBox(LPTSTR lpszFunction)

{

    // Retrieve the system error message for the last-error code

    LPVOID lpMsgBuf;

    LPVOID lpDisplayBuf;

    DWORD dw = GetLastError();

 

    FormatMessage(

        FORMAT_MESSAGE_ALLOCATE_BUFFER |

        FORMAT_MESSAGE_FROM_SYSTEM |

        FORMAT_MESSAGE_IGNORE_INSERTS,

        NULL,

        dw,

        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

        (LPTSTR) &lpMsgBuf,

        0, NULL );

 

    // Display the error message and clean up

    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT, (lstrlen((LPCTSTR)lpMsgBuf)+lstrlen((LPCTSTR)lpszFunction)+40)*sizeof(WCHAR));

    StringCchPrintf((LPTSTR)lpDisplayBuf, LocalSize(lpDisplayBuf) / sizeof(WCHAR),  L%s failed with error %d: %s, lpszFunction, dw, lpMsgBuf);

    MessageBox(NULL, (LPCTSTR)lpDisplayBuf, LError, MB_OK);

 

    LocalFree(lpMsgBuf);

    LocalFree(lpDisplayBuf);

}

 

 

Build and run the project. The following screenshot is a sample output.

 

 

 

 

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