examples: Add an example of using the mount-local API from C.

2 files changed, 171 insertions, 0 deletions

diff --git a/examples/Makefile.am b/examples/Makefile.am
index b6d9a865..81f22747 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -37,6 +37,9 @@ endif
 if HAVE_HIVEX
 noinst_PROGRAMS += virt-dhcp-address
 endif
+if HAVE_FUSE
+noinst_PROGRAMS += mount_local
+endif
 
 if HAVE_LIBVIRT
 copy_over_SOURCES = copy_over.c
@@ -75,6 +78,18 @@ inspect_vm_CFLAGS = \
 inspect_vm_LDADD = \
 	$(top_builddir)/src/libguestfs.la
 
+if HAVE_FUSE
+mount_local_SOURCES = mount_local.c
+mount_local_CFLAGS = \
+	-DGUESTFS_WARN_DEPRECATED=1 \
+	-I$(top_srcdir)/src -I$(top_builddir)/src \
+	$(FUSE_CFLAGS) \
+	$(WARN_CFLAGS) $(WERROR_CFLAGS)
+mount_local_LDADD = \
+	$(FUSE_LIBS) -lulockmgr \
+	$(top_builddir)/src/libguestfs.la
+endif
+
 if HAVE_HIVEX
 virt_dhcp_address_SOURCES = virt-dhcp-address.c
 virt_dhcp_address_CFLAGS = \
diff --git a/examples/mount_local.c b/examples/mount_local.c
new file mode 100644
index 00000000..526e426f
--- /dev/null
+++ b/examples/mount_local.c
@@ -0,0 +1,156 @@
+/* Demonstrate the use of the 'mount-local' API.
+ *
+ * Run this program as (eg) mount_local /tmp/test.img.  Note that
+ * '/tmp/test.img' is created or overwritten.  Follow the instructions
+ * on screen.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+
+#include <guestfs.h>
+
+static void
+usage (void)
+{
+  fprintf (stderr,
+           "Usage: mount_local disk.img\n"
+           "\n"
+           "NOTE: disk.img will be created or overwritten.\n"
+           "\n");
+}
+
+int
+main (int argc, char *argv[])
+{
+  guestfs_h *g;
+  int fd;
+  char tempdir[] = "/tmp/mlXXXXXX";
+  pid_t pid;
+  char *shell;
+
+  if (argc != 2) {
+    usage ();
+    exit (EXIT_FAILURE);
+  }
+
+  printf ("\n"
+          "This is the 'mount-local' demonstration program.  Follow the\n"
+          "instructions on screen.\n"
+          "\n"
+          "Creating and formatting the disk image, please wait a moment ...\n");
+  fflush (stdout);
+
+  /* Create the output disk image: 512 MB raw sparse. */
+  fd = open (argv[1], O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0644);
+  if (fd == -1) {
+    perror (argv[1]);
+    exit (EXIT_FAILURE);
+  }
+  if (ftruncate (fd, 512 * 1024 * 1024) == -1) {
+    perror ("truncate");
+    close (fd);
+    exit (EXIT_FAILURE);
+  }
+  if (close (fd) == -1) {
+    perror ("close");
+    exit (EXIT_FAILURE);
+  }
+
+  /* Open the disk image and format it with a partition and a filesystem. */
+  g = guestfs_create ();
+  if (g == NULL) {
+    perror ("could not create libguestfs handle");
+    exit (EXIT_FAILURE);
+  }
+
+  if (guestfs_add_drive_opts (g, argv[1],
+                              GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
+                              -1) == -1)
+    exit (EXIT_FAILURE);
+
+  if (guestfs_launch (g) == -1)
+    exit (EXIT_FAILURE);
+
+  if (guestfs_part_disk (g, "/dev/sda", "mbr") == -1)
+    exit (EXIT_FAILURE);
+
+  if (guestfs_mkfs (g, "ext2", "/dev/sda1") == -1)
+    exit (EXIT_FAILURE);
+
+  /* Mount the empty filesystem. */
+  if (guestfs_mount (g, "/dev/sda1", "/") == -1)
+    exit (EXIT_FAILURE);
+
+  /* Create a temporary mount directory. */
+  if (mkdtemp (tempdir) == NULL) {
+    perror ("mkdtemp");
+    exit (EXIT_FAILURE);
+  }
+
+  /* Mount the filesystem. */
+  if (guestfs_mount_local (g, tempdir, -1) == -1)
+    exit (EXIT_FAILURE);
+
+  /* Fork the shell for the user. */
+  pid = fork ();
+  if (pid == -1) {
+    perror ("fork");
+    exit (EXIT_FAILURE);
+  }
+
+  if (pid == 0) {               /* Child. */
+    if (chdir (tempdir) == -1) {
+      perror (tempdir);
+      _exit (EXIT_FAILURE);
+    }
+
+    printf ("\n"
+            "The _current directory_ is a FUSE filesystem backed by the disk\n"
+            "image which is managed by libguestfs.  Any files or directories\n"
+            "you copy into here (up to 512 MB) will be saved into the disk\n"
+            "image.  You can also delete files, create certain special files\n"
+            "and so on.\n"
+            "\n"
+            "When you have finished adding files, hit ^D or exit to exit the\n"
+            "shell and return to the mount-local program.\n"
+            "\n");
+
+    shell = getenv ("SHELL");
+    system (shell ? : "/bin/sh");
+
+    chdir ("/");
+    guestfs_umount_local (g, GUESTFS_UMOUNT_LOCAL_RETRY, 1, -1);
+    _exit (EXIT_SUCCESS);
+  }
+
+  /* Note that we are *not* waiting for the child yet.  We want to
+   * run the FUSE code in parallel with the subshell.
+   */
+  if (guestfs_mount_local_run (g) == -1)
+    exit (EXIT_FAILURE);
+
+  waitpid (pid, NULL, 0);
+
+  /* Unmount and close. */
+  if (guestfs_umount (g, "/") == -1)
+    exit (EXIT_FAILURE);
+
+  guestfs_close (g);
+
+  printf ("\n"
+          "Any files or directories that you copied in have been saved into\n"
+          "the disk image called '%s'.\n"
+          "\n"
+          "Try opening the disk image with guestfish to see those files:\n"
+          "\n"
+          "  guestfish -a %s -m /dev/sda1\n"
+          "\n",
+          argv[1], argv[1]);
+
+  exit (EXIT_SUCCESS);
+}