design.txt: New file

1 files changed, 31 insertions, 0 deletions

diff --git a/design.txt b/design.txt
new file mode 100644
index 0000000..844e9cb
--- /dev/null
+++ b/design.txt
@@ -0,0 +1,31 @@
+file_read(buffer, size, user_data)
+	file = user_data
+	return fread(buffer, 1, size, file)
+
+extract(file_name, outer_member, inner_action)
+	file = fopen(file_name, "rb")
+	outer_gzip  = gzip_init(&file_read, file)
+	outer_ustar = ustar_init(outer_gzip)
+	ustar_seek(outer_ustar, outer_member)
+	inner_gzip  = gzip_init(ustar_next_data_record, outer_ustar)
+	inner_ustar = ustar_init(inner_gzip)
+	inner_action(inner_ustar)
+
+print_data(data, size)
+	fwrite(data, 1, size, stdout)
+
+read_control(inner_ustar)
+	ustar_seek(inner_ustar, "control")
+	ustar_read(inner_ustar, &print_data)
+
+print_member(member)
+	printf("%s", member->name)
+
+list_members(inner_ustar)
+	ustar_list(inner_ustar, &print_member)
+
+main()
+	if -I
+		extract(argv[1], "control.tar.gz", &read_control)
+	else if -c
+		extract(argv[1], "data.tar.gz", &list_members)