pkgroot=/
+# allocate an install id, perhaps hash package and timestamp
+# extract pre-scripts and run them
+# get list of paths to install
+# for each path, if directory, create and set mode
+# for each path, create leading directories
+# extract to something like /var/tmp/.hash, with low perms
+# only atomic if same filesystem, so use .installid.hash in the
+# install directory
+# set perms and such
+# move into place
+# after all the files, extract post scripts and run them
+
# option for "multipackage" just to let the system know that's what you meant
# option to take filenames from stdin
# parse package, version, release from file if not given