GetFileVersionInfo

GetFileVersionInfo is a Windows API function used to retrieve version information from a binary file that contains a version resource. It is part of the Version Information API and is implemented by Version.dll. The function, together with GetFileVersionInfoSize and VerQueryValue, enables programs to read version strings and numeric version data embedded in executables, DLLs, and other files.

GetFileVersionInfoSize returns the size of the version information for the specified file. GetFileVersionInfo fills a buffer with the version data. The data is organized into a version resource containing VS_FIXEDFILEINFO and StringFileInfo blocks. The information is read from the file’s version resource rather than being parsed from arbitrary data.

Prototype and usage: DWORD GetFileVersionInfoSize(LPCTSTR lptstrFilename, LPDWORD lpdwHandle); BOOL GetFileVersionInfo(LPCTSTR lptstrFilename, DWORD dwHandle, DWORD dwLen, LPVOID lpData). You typically call GetFileVersionInfoSize to obtain a buffer size, allocate it, then call GetFileVersionInfo to populate the buffer. The dwHandle parameter for GetFileVersionInfo should be the value returned by GetFileVersionInfoSize for the file.

VerQueryValue is used to extract specific values, such as the numeric version in VS_FIXEDFILEINFO (dwFileVersionMS, dwFileVersionLS) and strings like "FileVersion" and "ProductVersion" from the StringFileInfo block. The function returns nonzero on success; zero indicates failure and GetLastError can be used for details. There are ANSI and Unicode variants (GetFileVersionInfoA and GetFileVersionInfoW); you typically link with Version.lib and include WinVer.h.