Platform SDK: Files and I/O

WIN32_FIND_DATA

The WIN32_FIND_DATA structure describes a file found by the FindFirstFile, FindFirstFileEx, or FindNextFile function.

typedef struct _WIN32_FIND_DATA {
  DWORD    dwFileAttributes; 
  FILETIME ftCreationTime; 
  FILETIME ftLastAccessTime; 
  FILETIME ftLastWriteTime; 
  DWORD    nFileSizeHigh; 
  DWORD    nFileSizeLow; 
  DWORD    dwReserved0; 
  DWORD    dwReserved1; 
  TCHAR    cFileName[ MAX_PATH ]; 
  TCHAR    cAlternateFileName[ 14 ]; 
} WIN32_FIND_DATA, *PWIN32_FIND_DATA; 

Members

dwFileAttributes
Specifies the file attributes of the file found. This member can be one or more of the following values.
Attribute Meaning
FILE_ATTRIBUTE_ARCHIVE The file or directory is an archive file or directory. Applications use this attribute to mark files for backup or removal.
FILE_ATTRIBUTE_COMPRESSED The file or directory is compressed. For a file, this means that all of the data in the file is compressed. For a directory, this means that compression is the default for newly created files and subdirectories.
FILE_ATTRIBUTE_DIRECTORY The handle identifies a directory.
FILE_ATTRIBUTE_ENCRYPTED The file or directory is encrypted. For a file, this means that all data in the file is encrypted. For a directory, this means that encryption is the default for newly created files and subdirectories.
FILE_ATTRIBUTE_HIDDEN The file or directory is hidden. It is not included in an ordinary directory listing.
FILE_ATTRIBUTE_NORMAL The file or directory has no other attributes set. This attribute is valid only if used alone.
FILE_ATTRIBUTE_OFFLINE The file data is not immediately available. This attribute indicates that the file data has been physically moved to offline storage. This attribute is used by Remote Storage, the hierarchical storage management software in Windows 2000. Applications should not arbitrarily change this attribute.
FILE_ATTRIBUTE_READONLY The file or directory is read-only. Applications can read the file but cannot write to it or delete it. In the case of a directory, applications cannot delete it.
FILE_ATTRIBUTE_REPARSE_POINT The file has an associated reparse point.
FILE_ATTRIBUTE_SPARSE_FILE The file is a sparse file.
FILE_ATTRIBUTE_SYSTEM The file or directory is part of the operating system or is used exclusively by the operating system.
FILE_ATTRIBUTE_TEMPORARY The file is being used for temporary storage. File systems attempt to keep all of the data in memory for quicker access, rather than flushing it back to mass storage. A temporary file should be deleted by the application as soon as it is no longer needed.

ftCreationTime
Specifies a FILETIME structure containing the time the file was created. FindFirstFile and FindNextFile report file times in Coordinated Universal Time (UTC) format. These functions set the FILETIME members to zero if the file system containing the file does not support this time member. You can use the FileTimeToLocalFileTime function to convert from UTC to local time, and then use the FileTimeToSystemTime function to convert the local time to a SYSTEMTIME structure containing individual members for the month, day, year, weekday, hour, minute, second, and millisecond.
ftLastAccessTime
Specifies a FILETIME structure containing the time that the file was last accessed. The time is in UTC format; the FILETIME members are zero if the file system does not support this time member.
ftLastWriteTime
Specifies a FILETIME structure containing the time that the file was last written to. The time is in UTC format; the FILETIME members are zero if the file system does not support this time member.
nFileSizeHigh
Specifies the high-order DWORD value of the file size, in bytes. This value is zero unless the file size is greater than MAXDWORD. The size of the file is equal to (nFileSizeHigh * (MAXDWORD+1)) + nFileSizeLow.
nFileSizeLow
Specifies the low-order DWORD value of the file size, in bytes.
dwReserved0
If the dwFileAttributes member includes the FILE_ATTRIBUTE_REPARSE_POINT attribute, this member specifies the reparse tag. Otherwise, this value is undefined and should not be used.
dwReserved1
Reserved for future use.
cFileName
A null-terminated string that is the name of the file.
cAlternateFileName
A null-terminated string that is an alternative name for the file. This name is in the classic 8.3 (filename.ext) file name format.

Remarks

If a file has a long file name, the complete name appears in the cFileName field, and the 8.3 format truncated version of the name appears in the cAlternateFileName field. Otherwise, cAlternateFileName is empty. As an alternative, you can use the GetShortPathName function to find the 8.3 format version of a file name.

Not all file systems can record creation and last access time and not all file systems record them in the same manner. For example, on Windows NT FAT, create time has a resolution of 10 milliseconds, write time has a resolution of 2 seconds, and access time has a resolution of 1 day (really, the access date). On NTFS, access time has a resolution of 1 hour. Furthermore, FAT records times on disk in local time, while NTFS records times on disk in UTC, so it is not affected by changes in time zone or daylight saving time.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Windows 95/98: Requires Windows 95 or later.
  Header: Declared in Winbase.h; include Windows.h.
  Unicode: Declared as Unicode and ANSI structures.

See Also

File I/O Overview, File I/O Structures, FILETIME, FindFirstFile, FindFirstFileEx, FindNextFile, FileTimeToLocalFileTime, FileTimeToSystemTime, GetShortPathName