GetFileVersion

GetFileVersionInfo is a Windows API routine used to retrieve version information embedded in the version resource of a file. It is commonly applied to executable files and dynamic-link libraries (exe, dll) that include a version resource. The retrieved data typically includes the file version, product version, and descriptive strings such as company name and file description.

In practice, GetFileVersionInfo is used in conjunction with GetFileVersionInfoSize to determine the required buffer size and with VerQueryValue to extract specific values. The version data is stored in a VS_FIXEDFILEINFO structure and may also be localized, requiring queries against translation tables to obtain language-specific strings.

Typical workflow: call GetFileVersionInfoSize with the target file name to determine the buffer size; allocate a buffer and call GetFileVersionInfo to fill it. Then call VerQueryValue with the root or specific sub-block (for example, "\\") to obtain a pointer to VS_FIXEDFILEINFO, which contains dwFileVersionMS, dwFileVersionLS, dwProductVersionMS, and dwProductVersionLS. To retrieve human-readable strings, query for "\\StringFileInfo\\<lang><codepage>\\Version" blocks or use "\\VarFileInfo\\Translation" to enumerate available languages.

The major, minor, build, and revision numbers are encoded in the high/low DWORDs of the version fields; the exact formatting can be converted into a string such as "major.minor.build.revision". The data is optional and may be missing if the file does not include a version resource. The API is available on Windows and requires proper permissions to read the file.