Add Erlang bindings.

[libguestfs.git] / erlang / examples / create_disk.erl

diff --git a/erlang/examples/create_disk.erl b/erlang/examples/create_disk.erl
new file mode 100755 (executable)
index 0000000..231c398
--- /dev/null
+++ b/erlang/examples/create_disk.erl
@@ -0,0 +1,65 @@
+#!/usr/bin/env escript
+%%! -smp enable -sname create_disk debug verbose
+% Example showing how to create a disk image.
+
+main(_) ->
+    Output = "disk.img",
+
+    {ok, G} = guestfs:create(),
+
+    % Create a raw-format sparse disk image, 512 MB in size.
+    {ok, File} = file:open(Output, [raw, write, binary]),
+    {ok, _} = file:position(File, 512 * 1024 * 1024 - 1),
+    ok = file:write(File, " "),
+    ok = file:close(File),
+
+    % Set the trace flag so that we can see each libguestfs call.
+    ok = guestfs:set_trace(G, true),
+
+    % Set the autosync flag so that the disk will be synchronized
+    % automatically when the libguestfs handle is closed.
+    ok = guestfs:set_autosync(G, true),
+
+    % Attach the disk image to libguestfs.
+    ok = guestfs:add_drive_opts(G, Output,
+                                [{format, "raw"}, {readonly, false}]),
+
+    % Run the libguestfs back-end.
+    ok = guestfs:launch(G),
+
+    % Get the list of devices.  Because we only added one drive
+    % above, we expect that this list should contain a single
+    % element.
+    [Device] = guestfs:list_devices(G),
+
+    % Partition the disk as one single MBR partition.
+    ok = guestfs:part_disk(G, Device, "mbr"),
+
+    % Get the list of partitions.  We expect a single element, which
+    % is the partition we have just created.
+    [Partition] = guestfs:list_partitions(G),
+
+    % Create a filesystem on the partition.
+    ok = guestfs:mkfs(G, "ext4", Partition),
+
+    % Now mount the filesystem so that we can add files. *)
+    ok = guestfs:mount_options(G, "", Partition, "/"),
+
+    % Create some files and directories. *)
+    ok = guestfs:touch(G, "/empty"),
+    Message = "Hello, world\n",
+    ok = guestfs:write(G, "/hello", Message),
+    ok = guestfs:mkdir(G, "/foo"),
+
+    % This one uploads the local file /etc/resolv.conf into
+    % the disk image.
+    ok = guestfs:upload(G, "/etc/resolv.conf", "/foo/resolv.conf"),
+
+    % Because 'autosync' was set (above) we can just close the handle
+    % and the disk contents will be synchronized.  You can also do
+    % this manually by calling guestfs:umount_all and guestfs:sync.
+    %
+    % Note also that handles are automatically closed if they are
+    % reaped by the garbage collector.  You only need to call close
+    % if you want to close the handle right away.
+    ok = guestfs:close(G).