df: Rewrite virt-df in C.

I have diffed the output from the original virt-df with this
new version, and they agree very closely.  Some differences:

 - Old virt-df have a divide-by-zero error in cases where the
   number of used inodes was 0.  New virt-df fixes this.

 - New virt-df uses gnulib human_readable library which displays
   numbers to 3 significant figures for -h output (old version
   used an ad hoc function).

1 files changed, 306 insertions, 0 deletions

diff --git a/df/main.c b/df/main.c
new file mode 100644
index 00000000..9565464b
--- /dev/null
+++ b/df/main.c
@@ -0,0 +1,306 @@
+/* virt-df
+ * Copyright (C) 2010 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 <stdint.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <assert.h>
+
+#ifdef HAVE_LIBVIRT
+#include <libvirt/libvirt.h>
+#include <libvirt/virterror.h>
+#endif
+
+#include "progname.h"
+
+#include "guestfs.h"
+#include "options.h"
+#include "virt-df.h"
+
+/* These globals are shared with options.c. */
+guestfs_h *g;
+
+int read_only = 1;
+int verbose = 0;
+int keys_from_stdin = 0;
+int echo_keys = 0;
+const char *libvirt_uri = NULL;
+int inspector = 0;
+
+int csv = 0;                    /* --csv */
+int human = 0;                  /* --human-readable|-h */
+int inodes = 0;                 /* --inodes */
+int one_per_guest = 0;          /* --one-per-guest */
+int uuid = 0;                   /* --uuid */
+
+static inline char *
+bad_cast (char const *s)
+{
+  return (char *) s;
+}
+
+static void __attribute__((noreturn))
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    fprintf (stderr, _("Try `%s --help' for more information.\n"),
+             program_name);
+  else {
+    fprintf (stdout,
+           _("%s: display free space on virtual filesystems\n"
+             "Copyright (C) 2010 Red Hat Inc.\n"
+             "Usage:\n"
+             "  %s [--options] -d domname\n"
+             "  %s [--options] -a disk.img [-a disk.img ...]\n"
+             "Options:\n"
+             "  -a|--add image       Add image\n"
+             "  -c|--connect uri     Specify libvirt URI for -d option\n"
+             "  --csv                Output as Comma-Separated Values\n"
+             "  -d|--domain guest    Add disks from libvirt guest\n"
+             "  --format[=raw|..]    Force disk format for -a option\n"
+             "  -h|--human-readable  Human-readable sizes in --long output\n"
+             "  --help               Display brief help\n"
+             "  -i|--inodes          Display inodes\n"
+             "  --one-per-guest      Separate appliance per guest\n"
+             "  --uuid               Add UUIDs to --long output\n"
+             "  -v|--verbose         Verbose messages\n"
+             "  -V|--version         Display version and exit\n"
+             "  -x                   Trace libguestfs API calls\n"
+             "For more information, see the manpage %s(1).\n"),
+             program_name, program_name, program_name,
+             program_name);
+  }
+  exit (status);
+}
+
+int
+main (int argc, char *argv[])
+{
+  /* Set global program name that is not polluted with libtool artifacts.  */
+  set_program_name (argv[0]);
+
+  setlocale (LC_ALL, "");
+  bindtextdomain (PACKAGE, LOCALEBASEDIR);
+  textdomain (PACKAGE);
+
+  enum { HELP_OPTION = CHAR_MAX + 1 };
+
+  static const char *options = "a:c:d:hivVx";
+  static const struct option long_options[] = {
+    { "add", 1, 0, 'a' },
+    { "connect", 1, 0, 'c' },
+    { "csv", 0, 0, 0 },
+    { "domain", 1, 0, 'd' },
+    { "format", 2, 0, 0 },
+    { "help", 0, 0, HELP_OPTION },
+    { "human-readable", 0, 0, 'h' },
+    { "inodes", 0, 0, 'i' },
+    { "one-per-guest", 0, 0, 0 },
+    { "uuid", 0, 0, 0 },
+    { "verbose", 0, 0, 'v' },
+    { "version", 0, 0, 'V' },
+    { 0, 0, 0, 0 }
+  };
+  struct drv *drvs = NULL;
+  struct drv *drv;
+  const char *format = NULL;
+  int c;
+  int option_index;
+
+  g = guestfs_create ();
+  if (g == NULL) {
+    fprintf (stderr, _("guestfs_create: failed to create handle\n"));
+    exit (EXIT_FAILURE);
+  }
+
+  argv[0] = bad_cast (program_name);
+
+  for (;;) {
+    c = getopt_long (argc, argv, options, long_options, &option_index);
+    if (c == -1) break;
+
+    switch (c) {
+    case 0:			/* options which are long only */
+      if (STREQ (long_options[option_index].name, "format")) {
+        if (!optarg || STREQ (optarg, ""))
+          format = NULL;
+        else
+          format = optarg;
+      } else if (STREQ (long_options[option_index].name, "csv")) {
+        csv = 1;
+      } else if (STREQ (long_options[option_index].name, "one-per-guest")) {
+        one_per_guest = 1;
+      } else if (STREQ (long_options[option_index].name, "uuid")) {
+        uuid = 1;
+      } else {
+        fprintf (stderr, _("%s: unknown long option: %s (%d)\n"),
+                 program_name, long_options[option_index].name, option_index);
+        exit (EXIT_FAILURE);
+      }
+      break;
+
+    case 'a':
+      OPTION_a;
+      break;
+
+    case 'c':
+      OPTION_c;
+      break;
+
+    case 'd':
+      OPTION_d;
+      break;
+
+    case 'h':
+      human = 1;
+      break;
+
+    case 'i':
+      inodes = 1;
+      break;
+
+    case 'v':
+      OPTION_v;
+      break;
+
+    case 'V':
+      OPTION_V;
+      break;
+
+    case 'x':
+      OPTION_x;
+      break;
+
+    case HELP_OPTION:
+      usage (EXIT_SUCCESS);
+
+    default:
+      usage (EXIT_FAILURE);
+    }
+  }
+
+  /* Old-style syntax?  There were no -a or -d options in the old
+   * virt-df which is how we detect this.
+   */
+  if (drvs == NULL) {
+    while (optind < argc) {
+      if (strchr (argv[optind], '/') ||
+          access (argv[optind], F_OK) == 0) { /* simulate -a option */
+        drv = malloc (sizeof (struct drv));
+        if (!drv) {
+          perror ("malloc");
+          exit (EXIT_FAILURE);
+        }
+        drv->type = drv_a;
+        drv->a.filename = argv[optind];
+        drv->a.format = NULL;
+        drv->next = drvs;
+        drvs = drv;
+      } else {                  /* simulate -d option */
+        drv = malloc (sizeof (struct drv));
+        if (!drv) {
+          perror ("malloc");
+          exit (EXIT_FAILURE);
+        }
+        drv->type = drv_d;
+        drv->d.guest = argv[optind];
+        drv->next = drvs;
+        drvs = drv;
+      }
+
+      optind++;
+    }
+  }
+
+  /* These are really constants, but they have to be variables for the
+   * options parsing code.  Assert here that they have known-good
+   * values.
+   */
+  assert (read_only == 1);
+  assert (inspector == 0);
+
+  /* Must be no extra arguments on the command line. */
+  if (optind != argc)
+    usage (EXIT_FAILURE);
+
+  /* -h and --csv doesn't make sense.  Spreadsheets will corrupt these
+   * fields.  (RHBZ#600977).
+   */
+  if (human && csv) {
+    fprintf (stderr, _("%s: you cannot use -h and --csv options together.\n"),
+             program_name);
+    exit (EXIT_FAILURE);
+  }
+
+  /* If the user didn't specify any drives, then we ask libvirt for
+   * the full list of guests and drives, which we add in batches.
+   */
+  if (drvs == NULL) {
+#ifdef HAVE_LIBVIRT
+    get_domains_from_libvirt ();
+#else
+    fprintf (stderr, _("%s: compiled without support for libvirt.\n"),
+             program_name);
+    exit (EXIT_FAILURE);
+#endif
+  }
+  else {
+    const char *name;
+
+    /* Add domains/drives from the command line (for a single guest). */
+    add_drives (drvs, 'a');
+
+    if (guestfs_launch (g) == -1)
+      exit (EXIT_FAILURE);
+
+    print_title ();
+
+    /* Synthesize a display name. */
+    switch (drvs->type) {
+    case drv_a:
+      name = strrchr (drvs->a.filename, '/');
+      break;
+    case drv_d:
+      name = drvs->d.guest;
+      break;
+    case drv_N:
+    default:
+      abort ();
+    }
+
+    /* XXX regression: in the Perl version we cached the UUID from the
+     * libvirt domain handle so it was available to us here.  In this
+     * version the libvirt domain handle is hidden inside
+     * guestfs_add_domain so the UUID is not available easily for
+     * single '-d' command-line options.
+     */
+    (void) df_on_handle (name, NULL, NULL, 0);
+
+    /* Free up data structures, no longer needed after this point. */
+    free_drives (drvs);
+  }
+
+  guestfs_close (g);
+
+  exit (EXIT_SUCCESS);
+}