/* rmdir -- remove directories

   Copyright (C) 1990-2020 Free Software Foundation, 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 3 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, see <https://www.gnu.org/licenses/>.  */

/* Options:
   -p, --parent		Remove any parent dirs that are explicitly mentioned
                        in an argument, if they become empty after the
                        argument file is removed.

   David MacKenzie <djm@ai.mit.edu>  */

#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>

#include "system.h"
#include "error.h"
#include "prog-fprintf.h"

/* The official name of this program (e.g., no 'g' prefix).  */
#define PROGRAM_NAME "rmdir"

#define AUTHORS proper_name ("David MacKenzie")

/* If true, remove empty parent directories.  */
static bool remove_empty_parents;

/* If true, don't treat failure to remove a nonempty directory
   as an error.  */
static bool ignore_fail_on_non_empty;

/* If true, output a diagnostic for every directory processed.  */
static bool verbose;

/* For long options that have no equivalent short option, use a
   non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
enum
{
  IGNORE_FAIL_ON_NON_EMPTY_OPTION = CHAR_MAX + 1
};

static struct option const longopts[] =
{
  /* Don't name this '--force' because it's not close enough in meaning
     to e.g. rm's -f option.  */
  {"ignore-fail-on-non-empty", no_argument, NULL,
   IGNORE_FAIL_ON_NON_EMPTY_OPTION},

  {"path", no_argument, NULL, 'p'},  /* Deprecated.  */
  {"parents", no_argument, NULL, 'p'},
  {"verbose", no_argument, NULL, 'v'},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {NULL, 0, NULL, 0}
};

/* Return true if ERROR_NUMBER is one of the values associated
   with a failed rmdir due to non-empty target directory.  */
static bool
errno_rmdir_non_empty (int error_number)
{
  return error_number == ENOTEMPTY || error_number == EEXIST;
}

/* Return true if when rmdir fails with errno == ERROR_NUMBER
   the directory may be non empty.  */
static bool
errno_may_be_non_empty (int error_number)
{
  switch (error_number)
    {
    case EACCES:
    case EPERM:
    case EROFS:
    case EBUSY:
      return true;
    default:
      return false;
    }
}

/* Return true if an rmdir failure with errno == error_number
   for DIR is ignorable.  */
static bool
ignorable_failure (int error_number, char const *dir)
{
  return (ignore_fail_on_non_empty
          && (errno_rmdir_non_empty (error_number)
              || (errno_may_be_non_empty (error_number)
                  && ! is_empty_dir (AT_FDCWD, dir)
                  && errno == 0 /* definitely non empty  */)));
}

/* Remove any empty parent directories of DIR.
   If DIR contains slash characters, at least one of them
   (beginning with the rightmost) is replaced with a NUL byte.
   Return true if successful.  */

static bool
remove_parents (char *dir)
{
  char *slash;
  bool ok = true;

  strip_trailing_slashes (dir);
  while (1)
    {
      slash = strrchr (dir, '/');
      if (slash == NULL)
        break;
      /* Remove any characters after the slash, skipping any extra
         slashes in a row. */
      while (slash > dir && *slash == '/')
        --slash;
      slash[1] = 0;

      /* Give a diagnostic for each attempted removal if --verbose.  */
      if (verbose)
        prog_fprintf (stdout, _("removing directory, %s"), quoteaf (dir));

      ok = (rmdir (dir) == 0);
      int rmdir_errno = errno;

      if (! ok)
        {
          /* Stop quietly if --ignore-fail-on-non-empty. */
          if (ignorable_failure (rmdir_errno, dir))
            {
              ok = true;
            }
          else
            {
              /* Barring race conditions, DIR is expected to be a directory.  */
              error (0, rmdir_errno, _("failed to remove directory %s"),
                     quoteaf (dir));
            }
          break;
        }
    }
  return ok;
}

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    emit_try_help ();
  else
    {
      printf (_("Usage: %s [OPTION]... DIRECTORY...\n"), program_name);
      fputs (_("\
Remove the DIRECTORY(ies), if they are empty.\n\
\n\
      --ignore-fail-on-non-empty\n\
                  ignore each failure that is solely because a directory\n\
                    is non-empty\n\
"), stdout);
      fputs (_("\
  -p, --parents   remove DIRECTORY and its ancestors; e.g., 'rmdir -p a/b/c' is\
\n\
                    similar to 'rmdir a/b/c a/b a'\n\
  -v, --verbose   output a diagnostic for every directory processed\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      emit_ancillary_info (PROGRAM_NAME);
    }
  exit (status);
}

int
main (int argc, char **argv)
{
  bool ok = true;
  int optc;

  initialize_main (&argc, &argv);
  set_program_name (argv[0]);
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  remove_empty_parents = false;

  while ((optc = getopt_long (argc, argv, "pv", longopts, NULL)) != -1)
    {
      switch (optc)
        {
        case 'p':
          remove_empty_parents = true;
          break;
        case IGNORE_FAIL_ON_NON_EMPTY_OPTION:
          ignore_fail_on_non_empty = true;
          break;
        case 'v':
          verbose = true;
          break;
        case_GETOPT_HELP_CHAR;
        case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
        default:
          usage (EXIT_FAILURE);
        }
    }

  if (optind == argc)
    {
      error (0, 0, _("missing operand"));
      usage (EXIT_FAILURE);
    }

  for (; optind < argc; ++optind)
    {
      char *dir = argv[optind];

      /* Give a diagnostic for each attempted removal if --verbose.  */
      if (verbose)
        prog_fprintf (stdout, _("removing directory, %s"), quoteaf (dir));

      if (rmdir (dir) != 0)
        {
          int rmdir_errno = errno;
          if (ignorable_failure (rmdir_errno, dir))
            continue;

          /* Here, the diagnostic is less precise, since we have no idea
             whether DIR is a directory.  */
          error (0, rmdir_errno, _("failed to remove %s"), quoteaf (dir));
          ok = false;
        }
      else if (remove_empty_parents)
        {
          ok &= remove_parents (dir);
        }
    }

  return ok ? EXIT_SUCCESS : EXIT_FAILURE;
}