How to retrieve a .dsc file giving only the pkg name

pkgurl=$(dcontrol $1 | grep ^Filename | head -1 | cut -d' ' -f 2 | sed s/_[a-zA-Z0-9]*.deb/.dsc/) dget -q http://ftp.uk.debian.org/debian/$pkgurl
dpkg-source -x $(basename $pkgurl)