-cat DEBIAN/control | sed --expression "s/Installed-Size: 0/Installed-Size: $SIZE/g" > DEBIAN/1.tmp
-mv DEBIAN/1.tmp DEBIAN/control
-cat DEBIAN/control | sed --expression "s/Version: 0/Version: $VER-$NR/g" > DEBIAN/1.tmp
-mv DEBIAN/1.tmp DEBIAN/control
+sed --in-place --expression "s/Installed-Size: 0/Installed-Size: $SIZE/g" DEBIAN/control
+sed --in-place --expression "s/Version: 0/Version: $VER-$NR/g" DEBIAN/control