Command line tool to dump Windows DLL version?

You can use PowerShell to get the information you want.

(Get-Item C:\Path\To\MyFile.dll).VersionInfo

By default this will display ProductVersion and FileVersion But the full VERSIONINFO is available. I.e. to return Comments

(Get-Item C:\Path\To\MyFile.dll).VersionInfo.Comments

Use Microsoft Sysinternals Sigcheck. This sample outputs just the version:

sigcheck -q -n foo.dll

Unpacked sigcheck.exe is only 228 KB.