url=https://www.kernel.org

port_getver() {
	fetch \
	| grep "Download complete tarball" \
	| grep -Eo $filename[_-][0-9a-z.]+.tar.[bgx]z2? \
	| sed "s/$filename[-_]//;s/\.tar.*//" \
	| grep "^4" \
	| grep -Evi '(alpha|beta|rc|pre)' \
	| grep [[:digit:]]
}