db-import-pkg: Add expac_file function, use it to list packages in DBs.

I don't actually care about using it to list the packages in the DBs right
now (but maybe I will if we ever change to blacklisting by pkgbase).

The reason for this change is so that I can later use expac to get PGP
signatures out of the DBs.

1 files changed, 24 insertions, 4 deletions

diff --git a/db-import-pkg b/db-import-pkg
index d05f4f8..a49f5e0 100755
--- a/db-import-pkg
+++ b/db-import-pkg
@@ -12,6 +12,29 @@ setup_traps
 
 readonly -a UPSTREAMS=(packages community archlinux{32,arm})
 
+# usage: expac_file <FILE.db> <EXPAC_ARGS>
+expac_file() {
+	local dbfile=$1
+	local args=("${@:2}")
+
+	local reponame=${dbfile##*/}
+	reponame=${reponame%%.*}
+
+	mkdir -p -- "${WORKDIR}/expac/root"
+	cat >"${WORKDIR}/expac/pacman.conf" <<-EOT
+	[options]
+	RootDir = ${WORKDIR}/expac/root
+	DBPath = ${WORKDIR}/expac/root
+
+	[${reponame}]
+	Server = file://$(realpath --no-symlinks -- "${dbfile%/*}")
+	EOT
+
+	fakeroot pacman --config="${WORKDIR}/expac/pacman.conf" -Syy >/dev/null
+	# expac exits with non-zero on emtpy databases, so ignore errors
+	expac --config="${WORKDIR}/expac/pacman.conf" --sync "${args[@]}" || true
+}
+
 # usage: fetch_dbs <from> <into>
 #
 # Fetch excluding everything but db files
@@ -41,10 +64,7 @@ get_repo_dir() {
 #
 #     pkgname [epoch:]pkgver-pkgrel
 db_list_pkgs() {
-	bsdtar tf "$1" |
-		cut -d "/" -f 1 |
-		sed -r 's/-([^-]*-[^-]*)$/ \1/' |
-		sort -u
+	expac_file "$1" '%n %v' | sort -u
 }
 
 # usage: filter_blacklisted <FULL_LIST >FILTERED_LIST