Add 'df' and 'df-h' commands.

df and df-h commands can be used interactively to show disk
space usage.

Use existing statvfs command from programs.

daemon/Makefile.am

@@ -29,6 +29,7 @@ guestfsd_SOURCES = \
 	daemon.h \
 	debug.c \
 	devsparts.c \
+	df.c \
 	dir.c \
 	dmesg.c \
 	dropcaches.c \

daemon/df.c

@@ -0,0 +1,70 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2009 Red Hat Inc. 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../src/guestfs_protocol.h"
+#include "daemon.h"
+#include "actions.h"
+
+char *
+do_df ()
+{
+  int r;
+  char *out, *err;
+
+  NEED_ROOT (NULL);
+
+  r = command (&out, &err, "df", NULL);
+  if (r == -1) {
+    reply_with_error ("df: %s", err);
+    free (out);
+    free (err);
+    return NULL;
+  }
+
+  free (err);
+
+  return out;			/* Caller frees. */
+}
+
+char *
+do_df_h ()
+{
+  int r;
+  char *out, *err;
+
+  NEED_ROOT (NULL);
+
+  r = command (&out, &err, "df", "-h", NULL);
+  if (r == -1) {
+    reply_with_error ("df -h: %s", err);
+    free (out);
+    free (err);
+    return NULL;
+  }
+
+  free (err);
+
+  return out;			/* Caller frees. */
+}

src/generator.ml

@@ -2558,6 +2558,31 @@ from the file C<path>, starting with the C<-nrlines>th line.
 
 If the parameter C<nrlines> is zero, this returns an empty list.");
 
+  ("df", (RString "output", []), 125, [],
+   [], (* XXX Tricky to test because it depends on the exact format
+	* of the 'df' command and other imponderables.
+	*)
+   "report file system disk space usage",
+   "\
+This command runs the C<df> command to report disk space used.
+
+This command is mostly useful for interactive sessions.  It
+is I<not> intended that you try to parse the output string.
+Use C<statvfs> from programs.");
+
+  ("df_h", (RString "output", []), 126, [],
+   [], (* XXX Tricky to test because it depends on the exact format
+	* of the 'df' command and other imponderables.
+	*)
+   "report file system disk space usage (human readable)",
+   "\
+This command runs the C<df -h> command to report disk space used
+in human-readable format.
+
+This command is mostly useful for interactive sessions.  It
+is I<not> intended that you try to parse the output string.
+Use C<statvfs> from programs.");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions