java: Add guestfs-java(3) man page.

[libguestfs.git] / java / examples / InspectVM.java

diff --git a/java/examples/InspectVM.java b/java/examples/InspectVM.java
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+// Example showing how to inspect a virtual machine disk.
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import com.redhat.et.libguestfs.*;
+
+public class InspectVM
+{
+    static final Comparator<String> COMPARE_KEYS_LEN =
+        new Comparator<String>() {
+        public int compare (String k1, String k2) {
+            return k1.length() - k2.length();
+        }
+    };
+
+    public static void main (String[] argv)
+    {
+        try {
+            if (argv.length != 1)
+                throw new Error ("usage: InspectVM disk.img");
+
+            String disk = argv[0];
+
+            GuestFS g = new GuestFS ();
+
+            // Attach the disk image read-only to libguestfs.
+            Map<String, Object> optargs = new HashMap<String, Object>() {
+                {
+                    //put ("format", "raw");
+                    put ("readonly", Boolean.TRUE);
+                }
+            };
+
+            g.add_drive_opts (disk, optargs);
+
+            // Run the libguestfs back-end.
+            g.launch ();
+
+            // Ask libguestfs to inspect for operating systems.
+            String roots[] = g.inspect_os ();
+            if (roots.length == 0)
+                throw new Error ("inspect_vm: no operating systems found");
+
+            for (String root : roots) {
+                System.out.println ("Root device: " + root);
+
+                // Print basic information about the operating system.
+                System.out.println ("  Product name: " +
+                                    g.inspect_get_product_name (root));
+                System.out.println ("  Version:      " +
+                                    g.inspect_get_major_version (root) +
+                                    "." +
+                                    g.inspect_get_minor_version (root));
+                System.out.println ("  Type:         " +
+                                    g.inspect_get_type (root));
+                System.out.println ("  Distro:       " +
+                                    g.inspect_get_distro (root));
+
+                // Mount up the disks, like guestfish -i.
+                //
+                // Sort keys by length, shortest first, so that we end up
+                // mounting the filesystems in the correct order.
+                Map<String,String> mps = g.inspect_get_mountpoints (root);
+                List<String> mps_keys = new ArrayList (mps.keySet ());
+                Collections.sort (mps_keys, COMPARE_KEYS_LEN);
+
+                for (String mp : mps_keys) {
+                    String dev = mps.get (mp);
+                    try {
+                        g.mount_ro (dev, mp);
+                    }
+                    catch (Exception exn) {
+                        System.err.println (exn + " (ignored)");
+                    }
+                }
+
+                // If /etc/issue.net file exists, print up to 3 lines.
+                String filename = "/etc/issue.net";
+                if (g.is_file (filename)) {
+                    System.out.println ("--- " + filename + " ---");
+                    String[] lines = g.head_n (3, filename);
+                    for (String line : lines)
+                        System.out.println (line);
+                }
+
+                // Unmount everything.
+                g.umount_all ();
+            }
+        }
+        catch (Exception exn) {
+            System.err.println (exn);
+            System.exit (1);
+        }
+    }
+}