Detect decompression tool automatically

This fixes cross-compilation from macOS, whose bsdtar does support
xz through liblzma, but does not have xz(1).

1 files changed, 18 insertions, 0 deletions

diff --git a/scripts/extract.sh b/scripts/extract.sh
new file mode 100644
index 00000000..1ffc23f8
--- /dev/null
+++ b/scripts/extract.sh
@@ -0,0 +1,18 @@
+file=$1
+shift
+
+case $file in
+*.tar.gz|*.tgz) tool=gzip  ;;
+*.tar.bz2)      tool=bzip2 ;;
+*.tar.xz)       tool=xz    ;;
+*) exit 0
+esac
+
+if command -v bsdtar >/dev/null; then
+	exec bsdtar -xf "$file" "$@"
+elif command -v pax >/dev/null; then
+	"$tool" -d -c "$file" | pax "$@"
+else
+	printf '%s: bsdtar or pax is required' "$0" >&2
+	exit 1
+fi