Exiv2

Strangle - exiv2 does not have any support for svg yet - and even more strangely the manpage
http://www.exiv2.org/manpage.html
fails to list it as an image file type???? Really strange.

The meta data is straight forward DC xml..

$ grep grep "dc." example.svg
xmlns:dc="http://purl.org/dc/elements/1.1/"
<dc:format>image/svg+xml</dc:format>
<dc:type
rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
<dc:title></dc:title>
<dc:rights>
<dc:title>© 2015 Example, Inc. All rights reserved.</dc:title>
</dc:rights>
<dc:creator>
<dc:title>Jonathon Doe</dc:title>
</dc:creator>

The standards for svg are well documented - http://www.w3.org/TR/SVG11/

inkscape ( https://inkscape.org/en/ ) - a rather nice GUI svg editor can edit the meta data - but nothing I've found can do it via scripts.

IMO it seems important for exiv2 to support svg. If someone writes the code - please flag me to help with testing.