The MsiGetFileHash function takes the path to a file and returns a 128-bit hash of that file. Authoring tools may use MsiGetFileHash to obtain the file hash needed to populate the MsiFileHash table.

Windows Installer uses file hashing as a means to detect and eliminate unnecessary file copying. A file hash stored in the MsiFileHash table may be compared to a hash of an existing file on the user's computer.

Syntax

C++UINT MsiGetFileHash(
  __in   LPCTSTR szFilePath,
  __in   DWORD dwOptions,
  __out  PMSIFILEHASHINFO pHash
);

Parameters

szFilePath [in]

Path to file that is to be hashed.

dwOptions [in]

The value in this column must be 0. This parameter is reserved for future use.

pHash [out]

Pointer to the returned file hash information.

Return Value

Remarks

The entire 128-bit file hash is returned as four 32-bit fields. The numbering of the four fields is zero-based. The values returned by MsiGetFileHash correspond to the four fields of the MSIFILEHASHINFO structure. The first field corresponds to the HashPart1 column of the MsiFileHash table, the second field corresponds to the HashPart2 column, the third field corresponds to the HashPart3 column, and the fourth field corresponds to the HashPart4 column.

The hash information entered into the MsiFileHash table must be obtained by calling MsiGetFileHash or the FileHash method. Do not attempt to use other methods to generate the file hash.

Requirements

See Also

MsiFileHash table

MSIFILEHASHINFO

Default File Versioning

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Build date: 8/13/2009