file mkdir $pkgdir $::teapotclient::pkgcachedir

			set url "http://$server/package/name/$extension/ver/$ver/arch/$arch/file"
			set urlcachefile [file join $::teapotclient::pkgcachedir [::md5::md5 -hex $url]]

			if {![file exists $urlcachefile]} {
				set tmpfd [open $urlcachefile w]
				fconfigure $tmpfd -encoding binary -translation binary -buffering none

				set token [::http::geturl $url -binary true -channel $tmpfd]

				::http::cleanup $token
				close $tmpfd
			}

			set retarr($extension) [list $ver $arch $server]
			switch -regexp -- [::fileutil::fileType $urlcachefile] {