path: root/inspector/virt-inspector.c

/* virt-inspector
 * Copyright (C) 2010-2011 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 <inttypes.h>
#include <unistd.h>
#include <getopt.h>
#include <locale.h>
#include <assert.h>

#include <libxml/xmlIO.h>
#include <libxml/xmlwriter.h>

#include "progname.h"
#include "c-ctype.h"

#include "guestfs.h"
#include "options.h"

/* Currently open libguestfs handle. */
guestfs_h *g;

int read_only = 1;
int live = 0;
int verbose = 0;
int keys_from_stdin = 0;
int echo_keys = 0;
const char *libvirt_uri = NULL;
int inspector = 1;

static void output (char **roots);
static void output_roots (xmlTextWriterPtr xo, char **roots);
static void output_root (xmlTextWriterPtr xo, char *root);
static void output_mountpoints (xmlTextWriterPtr xo, char *root);
static void output_filesystems (xmlTextWriterPtr xo, char *root);
static void output_drive_mappings (xmlTextWriterPtr xo, char *root);
static void output_applications (xmlTextWriterPtr xo, char *root);
static void canonicalize (char *dev);
static void free_strings (char **argv);
static int count_strings (char *const*argv);

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 information about a virtual machine\n"
             "Copyright (C) 2010 Red Hat Inc.\n"
             "Usage:\n"
             "  %s [--options] -d domname file [file ...]\n"
             "  %s [--options] -a disk.img [-a disk.img ...] file [file ...]\n"
             "Options:\n"
             "  -a|--add image       Add image\n"
             "  -c|--connect uri     Specify libvirt URI for -d option\n"
             "  -d|--domain guest    Add disks from libvirt guest\n"
             "  --echo-keys          Don't turn off echo for passphrases\n"
             "  --format[=raw|..]    Force disk format for -a option\n"
             "  --help               Display brief help\n"
             "  --keys-from-stdin    Read passphrases from stdin\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:vVx";
  static const struct option long_options[] = {
    { "add", 1, 0, 'a' },
    { "connect", 1, 0, 'c' },
    { "domain", 1, 0, 'd' },
    { "echo-keys", 0, 0, 0 },
    { "format", 2, 0, 0 },
    { "help", 0, 0, HELP_OPTION },
    { "keys-from-stdin", 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, "keys-from-stdin")) {
        keys_from_stdin = 1;
      } else if (STREQ (long_options[option_index].name, "echo-keys")) {
        echo_keys = 1;
      } else if (STREQ (long_options[option_index].name, "format")) {
        if (!optarg || STREQ (optarg, ""))
          format = NULL;
        else
          format = optarg;
      } 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':
      usage (EXIT_SUCCESS);

    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-inspector 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 == 1);
  assert (live == 0);

  /* Must be no extra arguments on the command line. */
  if (optind != argc)
    usage (EXIT_FAILURE);

  /* User must have specified some drives. */
  if (drvs == NULL)
    usage (EXIT_FAILURE);

  /* Add drives, inspect and mount.  Note that inspector is always true,
   * and there is no -m option.
   */
  add_drives (drvs, 'a');

  if (guestfs_launch (g) == -1)
    exit (EXIT_FAILURE);

  /* Free up data structures, no longer needed after this point. */
  free_drives (drvs);

  /* NB. Can't call inspect_mount () here (ie. normal processing of
   * the -i option) because it can only handle a single root.  So we
   * use low-level APIs.
   */
  inspect_do_decrypt ();

  char **roots = guestfs_inspect_os (g);
  if (roots == NULL) {
    fprintf (stderr, _("%s: no operating system could be detected inside this disk image.\n\nThis may be because the file is not a disk image, or is not a virtual machine\nimage, or because the OS type is not understood by libguestfs.\n\nNOTE for Red Hat Enterprise Linux 6 users: for Windows guest support you must\ninstall the separate libguestfs-winsupport package.\n\nIf you feel this is an error, please file a bug report including as much\ninformation about the disk image as possible.\n"),
             program_name);
    exit (EXIT_FAILURE);
  }

  output (roots);

  free_strings (roots);

  guestfs_close (g);

  exit (EXIT_SUCCESS);
}

#define DISABLE_GUESTFS_ERRORS_FOR(stmt) do {                           \
    guestfs_error_handler_cb old_error_cb;                              \
    void *old_error_data;                                               \
    old_error_cb = guestfs_get_error_handler (g, &old_error_data);      \
    guestfs_set_error_handler (g, NULL, NULL);                          \
    stmt;                                                               \
    guestfs_set_error_handler (g, old_error_cb, old_error_data);        \
  } while (0)

#define XMLERROR(code,e) do {                                           \
    if ((e) == (code)) {                                                \
      fprintf (stderr, _("%s: XML write error at \"%s\": %m\n"),        \
               #e, program_name);                                       \
      exit (EXIT_FAILURE);                                              \
    }                                                                   \
  } while (0)

static void
output (char **roots)
{
  xmlOutputBufferPtr ob = xmlOutputBufferCreateFd (1, NULL);
  if (ob == NULL) {
    fprintf (stderr,
             _("%s: xmlOutputBufferCreateFd: failed to open stdout\n"),
             program_name);
    exit (EXIT_FAILURE);
  }

  xmlTextWriterPtr xo = xmlNewTextWriter (ob);
  if (xo == NULL) {
    fprintf (stderr,
             _("%s: xmlNewTextWriter: failed to create libxml2 writer\n"),
             program_name);
    exit (EXIT_FAILURE);
  }

  /* Pretty-print the output. */
  XMLERROR (-1, xmlTextWriterSetIndent (xo, 1));
  XMLERROR (-1, xmlTextWriterSetIndentString (xo, BAD_CAST "  "));

  XMLERROR (-1, xmlTextWriterStartDocument (xo, NULL, NULL, NULL));
  output_roots (xo, roots);
  XMLERROR (-1, xmlTextWriterEndDocument (xo));

  /* 'ob' is freed by this too. */
  xmlFreeTextWriter (xo);
}

static void
output_roots (xmlTextWriterPtr xo, char **roots)
{
  size_t i;

  XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "operatingsystems"));
  for (i = 0; roots[i] != NULL; ++i)
    output_root (xo, roots[i]);
  XMLERROR (-1, xmlTextWriterEndElement (xo));
}

static void
output_root (xmlTextWriterPtr xo, char *root)
{
  char *str;
  int i, r;
  char buf[32];
  char canonical_root[strlen (root) + 1];

  XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "operatingsystem"));

  strcpy (canonical_root, root);
  canonicalize (canonical_root);
  XMLERROR (-1,
    xmlTextWriterWriteElement (xo, BAD_CAST "root", BAD_CAST canonical_root));

  str = guestfs_inspect_get_type (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "name", BAD_CAST str));
  free (str);

  str = guestfs_inspect_get_arch (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "arch", BAD_CAST str));
  free (str);

  str = guestfs_inspect_get_distro (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "distro", BAD_CAST str));
  free (str);

  str = guestfs_inspect_get_product_name (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "product_name", BAD_CAST str));
  free (str);

  str = guestfs_inspect_get_product_variant (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "product_variant", BAD_CAST str));
  free (str);

  i = guestfs_inspect_get_major_version (g, root);
  snprintf (buf, sizeof buf, "%d", i);
  XMLERROR (-1,
    xmlTextWriterWriteElement (xo, BAD_CAST "major_version", BAD_CAST buf));
  i = guestfs_inspect_get_minor_version (g, root);
  snprintf (buf, sizeof buf, "%d", i);
  XMLERROR (-1,
    xmlTextWriterWriteElement (xo, BAD_CAST "minor_version", BAD_CAST buf));

  str = guestfs_inspect_get_package_format (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "package_format", BAD_CAST str));
  free (str);

  str = guestfs_inspect_get_package_management (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "package_management",
                                 BAD_CAST str));
  free (str);

  /* inspect-get-windows-systemroot will fail with non-windows guests,
   * or if the systemroot could not be determined for a windows guest.
   * Disable error output around this call.
   */
  DISABLE_GUESTFS_ERRORS_FOR (
    str = guestfs_inspect_get_windows_systemroot (g, root);
    if (str)
      XMLERROR (-1,
                xmlTextWriterWriteElement (xo, BAD_CAST "windows_systemroot",
                                           BAD_CAST str));
    free (str);
  );
  DISABLE_GUESTFS_ERRORS_FOR (
    str = guestfs_inspect_get_windows_current_control_set (g, root);
    if (str)
      XMLERROR (-1,
                xmlTextWriterWriteElement (xo, BAD_CAST "windows_current_control_set",
                                           BAD_CAST str));
    free (str);
  );

  str = guestfs_inspect_get_format (g, root);
  if (!str) exit (EXIT_FAILURE);
  if (STRNEQ (str, "unknown"))
    XMLERROR (-1,
      xmlTextWriterWriteElement (xo, BAD_CAST "format",
                                 BAD_CAST str));
  free (str);

  r = guestfs_inspect_is_live (g, root);
  if (r > 0) {
    XMLERROR (-1,
              xmlTextWriterStartElement (xo, BAD_CAST "live"));
    XMLERROR (-1, xmlTextWriterEndElement (xo));
  }

  r = guestfs_inspect_is_netinst (g, root);
  if (r > 0) {
    XMLERROR (-1,
              xmlTextWriterStartElement (xo, BAD_CAST "netinst"));
    XMLERROR (-1, xmlTextWriterEndElement (xo));
  }

  r = guestfs_inspect_is_multipart (g, root);
  if (r > 0) {
    XMLERROR (-1,
              xmlTextWriterStartElement (xo, BAD_CAST "multipart"));
    XMLERROR (-1, xmlTextWriterEndElement (xo));
  }

  output_mountpoints (xo, root);

  output_filesystems (xo, root);

  output_drive_mappings (xo, root);

  output_applications (xo, root);

  XMLERROR (-1, xmlTextWriterEndElement (xo));
}

static int
compare_keys (const void *p1, const void *p2)
{
  const char *key1 = * (char * const *) p1;
  const char *key2 = * (char * const *) p2;

  return strcmp (key1, key2);
}

static int
compare_keys_nocase (const void *p1, const void *p2)
{
  const char *key1 = * (char * const *) p1;
  const char *key2 = * (char * const *) p2;

  return strcasecmp (key1, key2);
}

static int
compare_keys_len (const void *p1, const void *p2)
{
  const char *key1 = * (char * const *) p1;
  const char *key2 = * (char * const *) p2;
  int c;

  c = strlen (key1) - strlen (key2);
  if (c != 0)
    return c;

  return compare_keys (p1, p2);
}

static void
output_mountpoints (xmlTextWriterPtr xo, char *root)
{
  char **mountpoints;
  size_t i;

  mountpoints = guestfs_inspect_get_mountpoints (g, root);
  if (mountpoints == NULL)
    exit (EXIT_FAILURE);

  /* Sort by key length, shortest key first, and then name, so the
   * output is stable.
   */
  qsort (mountpoints, count_strings (mountpoints) / 2, 2 * sizeof (char *),
         compare_keys_len);

  XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "mountpoints"));

  for (i = 0; mountpoints[i] != NULL; i += 2) {
    canonicalize (mountpoints[i+1]);

    XMLERROR (-1,
              xmlTextWriterStartElement (xo, BAD_CAST "mountpoint"));
    XMLERROR (-1,
              xmlTextWriterWriteAttribute (xo, BAD_CAST "dev",
                                           BAD_CAST mountpoints[i+1]));
    XMLERROR (-1,
              xmlTextWriterWriteString (xo, BAD_CAST mountpoints[i]));
    XMLERROR (-1, xmlTextWriterEndElement (xo));
  }

  XMLERROR (-1, xmlTextWriterEndElement (xo));

  free_strings (mountpoints);
}

static void
output_filesystems (xmlTextWriterPtr xo, char *root)
{
  char **filesystems;
  char *str;
  size_t i;

  filesystems = guestfs_inspect_get_filesystems (g, root);
  if (filesystems == NULL)
    exit (EXIT_FAILURE);

  /* Sort by name so the output is stable. */
  qsort (filesystems, count_strings (filesystems), sizeof (char *),
         compare_keys);

  XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "filesystems"));

  for (i = 0; filesystems[i] != NULL; ++i) {
    canonicalize (filesystems[i]);

    XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "filesystem"));
    XMLERROR (-1,
              xmlTextWriterWriteAttribute (xo, BAD_CAST "dev",
                                           BAD_CAST filesystems[i]));

    DISABLE_GUESTFS_ERRORS_FOR (
      str = guestfs_vfs_type (g, filesystems[i]);
      if (str && str[0])
        XMLERROR (-1,
                  xmlTextWriterWriteElement (xo, BAD_CAST "type",
                                             BAD_CAST str));
      free (str);
    );

    DISABLE_GUESTFS_ERRORS_FOR (
      str = guestfs_vfs_label (g, filesystems[i]);
      if (str && str[0])
        XMLERROR (-1,
                  xmlTextWriterWriteElement (xo, BAD_CAST "label",
                                             BAD_CAST str));
      free (str);
    );

    DISABLE_GUESTFS_ERRORS_FOR (
      str = guestfs_vfs_uuid (g, filesystems[i]);
      if (str && str[0])
        XMLERROR (-1,
                  xmlTextWriterWriteElement (xo, BAD_CAST "uuid",
                                             BAD_CAST str));
      free (str);
    );

    XMLERROR (-1, xmlTextWriterEndElement (xo));
  }

  XMLERROR (-1, xmlTextWriterEndElement (xo));

  free_strings (filesystems);
}

static void
output_drive_mappings (xmlTextWriterPtr xo, char *root)
{
  char **drive_mappings = NULL;
  size_t i;

  DISABLE_GUESTFS_ERRORS_FOR (
    drive_mappings = guestfs_inspect_get_drive_mappings (g, root);
  );
  if (drive_mappings == NULL)
    return;

  if (drive_mappings[0] == NULL) {
    free_strings (drive_mappings);
    return;
  }

  /* Sort by key. */
  qsort (drive_mappings,
         count_strings (drive_mappings) / 2, 2 * sizeof (char *),
         compare_keys_nocase);

  XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "drive_mappings"));

  for (i = 0; drive_mappings[i] != NULL; i += 2) {
    canonicalize (drive_mappings[i+1]);

    XMLERROR (-1,
              xmlTextWriterStartElement (xo, BAD_CAST "drive_mapping"));
    XMLERROR (-1,
              xmlTextWriterWriteAttribute (xo, BAD_CAST "name",
                                           BAD_CAST drive_mappings[i]));
    XMLERROR (-1,
              xmlTextWriterWriteString (xo, BAD_CAST drive_mappings[i+1]));
    XMLERROR (-1, xmlTextWriterEndElement (xo));
  }

  XMLERROR (-1, xmlTextWriterEndElement (xo));

  free_strings (drive_mappings);
}

static void
output_applications (xmlTextWriterPtr xo, char *root)
{
  struct guestfs_application_list *apps;
  size_t i;

  /* We need to mount everything up in order to read out the list of
   * applications.
   */
  inspect_mount_root (root);

  /* This returns an empty list if we simply couldn't determine the
   * applications, so if it returns NULL then it's a real error.
   */
  apps = guestfs_inspect_list_applications (g, root);
  if (apps == NULL)
    exit (EXIT_FAILURE);
  if (guestfs_umount_all (g) == -1)
    exit (EXIT_FAILURE);

  XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "applications"));

  for (i = 0; i < apps->len; ++i) {
    XMLERROR (-1, xmlTextWriterStartElement (xo, BAD_CAST "application"));

    assert (apps->val[i].app_name && apps->val[i].app_name[0]);
    XMLERROR (-1,
              xmlTextWriterWriteElement (xo, BAD_CAST "name",
                                         BAD_CAST apps->val[i].app_name));

    if (apps->val[i].app_display_name && apps->val[i].app_display_name[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "display_name",
                                   BAD_CAST apps->val[i].app_display_name));

    if (apps->val[i].app_epoch != 0) {
      char buf[32];

      snprintf (buf, sizeof buf, "%d", apps->val[i].app_epoch);

      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "epoch", BAD_CAST buf));
    }

    if (apps->val[i].app_version && apps->val[i].app_version[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "version",
                                   BAD_CAST apps->val[i].app_version));
    if (apps->val[i].app_release && apps->val[i].app_release[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "release",
                                   BAD_CAST apps->val[i].app_release));
    if (apps->val[i].app_install_path && apps->val[i].app_install_path[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "install_path",
                                   BAD_CAST apps->val[i].app_install_path));
    if (apps->val[i].app_publisher && apps->val[i].app_publisher[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "publisher",
                                   BAD_CAST apps->val[i].app_publisher));
    if (apps->val[i].app_url && apps->val[i].app_url[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "url",
                                   BAD_CAST apps->val[i].app_url));
    if (apps->val[i].app_source_package && apps->val[i].app_source_package[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "source_package",
                                   BAD_CAST apps->val[i].app_source_package));
    if (apps->val[i].app_summary && apps->val[i].app_summary[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "summary",
                                   BAD_CAST apps->val[i].app_summary));
    if (apps->val[i].app_description && apps->val[i].app_description[0])
      XMLERROR (-1,
        xmlTextWriterWriteElement (xo, BAD_CAST "description",
                                   BAD_CAST apps->val[i].app_description));

    XMLERROR (-1, xmlTextWriterEndElement (xo));
  }

  XMLERROR (-1, xmlTextWriterEndElement (xo));

  guestfs_free_application_list (apps);
}

/* "/dev/vda1" -> "/dev/sda1"
 * See BLOCK DEVICE NAMING in guestfs(3).
 */
static void
canonicalize (char *dev)
{
  if (STRPREFIX (dev, "/dev/") &&
      (dev[5] == 'h' || dev[5] == 'v') &&
      dev[6] == 'd' &&
      c_isalpha (dev[7]) &&
      (c_isdigit (dev[8]) || dev[8] == '\0'))
    dev[5] = 's';
}

static void
free_strings (char **argv)
{
  int argc;

  for (argc = 0; argv[argc] != NULL; ++argc)
    free (argv[argc]);
  free (argv);
}

static int
count_strings (char *const *argv)
{
  int c;

  for (c = 0; argv[c]; ++c)
    ;
  return c;
}