coreutils/src/rm.c

/* `rm' file deletion utility for GNU.
   Copyright (C) 88, 90, 91, 1994-2006 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 2, 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

/* Written by Paul Rubin, David MacKenzie, and Richard Stallman.
   Reworked to use chdir and avoid recursion by Jim Meyering.  */

/* Implementation overview:

   In the `usual' case, RM saves no state for directories it is processing.
   When a removal fails (either due to an error or to an interactive `no'
   reply), the failure is noted (see description of `ht' in remove.c's
   remove_cwd_entries function) so that when/if the containing directory
   is reopened, RM doesn't try to remove the entry again.

   RM may delete arbitrarily deep hierarchies -- even ones in which file
   names (from root to leaf) are longer than the system-imposed maximum.
   It does this by using chdir to change to each directory in turn before
   removing the entries in that directory.

   RM detects directory cycles lazily.  See lib/cycle-check.c.

   RM is careful to avoid forming full file names whenever possible.
   A full file name is formed only when it is about to be used -- e.g.
   in a diagnostic or in an interactive-mode prompt.

   RM minimizes the number of lstat system calls it makes.  On systems
   that have valid d_type data in directory entries, RM makes only one
   lstat call per command line argument -- regardless of the depth of
   the hierarchy.  */

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

#include "system.h"
#include "argmatch.h"
#include "dirname.h"
#include "error.h"
#include "lstat.h"
#include "quote.h"
#include "quotearg.h"
#include "remove.h"
#include "root-dev-ino.h"
#include "yesno.h"

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

#define AUTHORS \
  "Paul Rubin", "David MacKenzie, Richard Stallman", "Jim Meyering"

/* Name this program was run with.  */
char *program_name;

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

enum interactive_type
  {
    interactive_never,		/* 0: no option or --interactive=never */
    interactive_once,		/* 1: -I or --interactive=once */
    interactive_always		/* 2: default, -i or --interactive=always */
  };

static struct option const long_opts[] =
{
  {"directory", no_argument, NULL, 'd'},
  {"force", no_argument, NULL, 'f'},
  {"interactive", optional_argument, NULL, INTERACTIVE_OPTION},

  {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  {"preserve-root", no_argument, NULL, PRESERVE_ROOT},

  /* This is solely for testing.  Do not document.  */
  /* It is relatively difficult to ensure that there is a tty on stdin.
     Since rm acts differently depending on that, without this option,
     it'd be harder to test the parts of rm that depend on that setting.  */
  {"-presume-input-tty", no_argument, NULL, PRESUME_INPUT_TTY_OPTION},

  {"recursive", no_argument, NULL, 'r'},
  {"verbose", no_argument, NULL, 'v'},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {NULL, 0, NULL, 0}
};

static char const *const interactive_args[] =
{
  "never", "no", "none",
  "once",
  "always", "yes", NULL
};
static enum interactive_type const interactive_types[] =
{
  interactive_never, interactive_never, interactive_never,
  interactive_once,
  interactive_always, interactive_always
};
ARGMATCH_VERIFY (interactive_args, interactive_types);

/* Advise the user about invalid usages like "rm -foo" if the file
   "-foo" exists, assuming ARGC and ARGV are as with `main'.  */

static void
diagnose_leading_hyphen (int argc, char **argv)
{
  /* OPTIND is unreliable, so iterate through the arguments looking
     for a file name that looks like an option.  */
  int i;

  for (i = 1; i < argc; i++)
    {
      char const *arg = argv[i];
      struct stat st;

      if (arg[0] == '-' && arg[1] && lstat (arg, &st) == 0)
	{
	  fprintf (stderr,
		   _("Try `%s ./%s' to remove the file %s.\n"),
		   argv[0],
		   quotearg_n_style (1, shell_quoting_style, arg),
		   quote (arg));
	  break;
	}
    }
}

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
	     program_name);
  else
    {
      printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
      fputs (_("\
Remove (unlink) the FILE(s).\n\
\n\
  -f, --force           ignore nonexistent files, never prompt\n\
  -i                    prompt before every removal\n\
"), stdout);
      fputs (_("\
  -I                    prompt once before removing more than three files, or\n\
                          when removing recursively.  Less intrusive than -i,\n\
                          while still giving protection against most mistakes\n\
      --interactive[=WHEN]  prompt according to WHEN: never, once (-I), or\n\
                          always (-i).  Without WHEN, prompt always\n\
"), stdout);
      fputs (_("\
      --no-preserve-root  do not treat `/' specially (the default)\n\
      --preserve-root   fail to operate recursively on `/'\n\
  -r, -R, --recursive   remove directories and their contents recursively\n\
  -v, --verbose         explain what is being done\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
By default, rm does not remove directories.  Use the --recursive (-r or -R)\n\
option to remove each listed directory, too, along with all of its contents.\n\
"), stdout);
      printf (_("\
\n\
To remove a file whose name starts with a `-', for example `-foo',\n\
use one of these commands:\n\
  %s -- -foo\n\
\n\
  %s ./-foo\n\
"),
	      program_name, program_name);
      fputs (_("\
\n\
Note that if you use rm to remove a file, it is usually possible to recover\n\
the contents of that file.  If you want more assurance that the contents are\n\
truly unrecoverable, consider using shred.\n\
"), stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status);
}

static void
rm_option_init (struct rm_options *x)
{
  x->ignore_missing_files = false;
  x->interactive = false;
  x->recursive = false;
  x->root_dev_ino = NULL;
  x->stdin_tty = isatty (STDIN_FILENO);
  x->verbose = false;

  /* Since this program exits immediately after calling `rm', rm need not
     expend unnecessary effort to preserve the initial working directory.  */
  x->require_restore_cwd = false;
}

int
main (int argc, char **argv)
{
  bool preserve_root = false;
  struct rm_options x;
  bool prompt_once = false;
  int c;

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

  atexit (close_stdout);

  rm_option_init (&x);

  while ((c = getopt_long (argc, argv, "dfirvIR", long_opts, NULL)) != -1)
    {
      switch (c)
	{
	case 'd':
	  /* Ignore this option, for backward compatibility with
	     coreutils 5.92.  Some time after 2005, we'll change this
	     to report an error (or perhaps behave like FreeBSD does)
	     instead of ignoring the option.  */
	  break;

	case 'f':
	  x.interactive = false;
	  x.ignore_missing_files = true;
	  prompt_once = false;
	  break;

	case 'i':
	  x.interactive = true;
	  x.ignore_missing_files = false;
	  prompt_once = false;
	  break;

	case 'I':
	  x.interactive = false;
	  x.ignore_missing_files = false;
	  prompt_once = true;
	  break;

	case 'r':
	case 'R':
	  x.recursive = true;
	  break;

	case INTERACTIVE_OPTION:
	  {
	    int i;
	    if (optarg)
	      i = XARGMATCH ("--interactive", optarg, interactive_args,
			     interactive_types);
	    else
	      i = interactive_always;
	    switch (i)
	      {
	      case interactive_never:
		x.interactive = false;
		prompt_once = false;
		break;

	      case interactive_once:
		x.interactive = false;
		x.ignore_missing_files = false;
		prompt_once = true;
		break;

	      case interactive_always:
		x.interactive = true;
		x.ignore_missing_files = false;
		prompt_once = false;
		break;
	      }
	    break;
	  }

	case NO_PRESERVE_ROOT:
	  preserve_root = false;
	  break;

	case PRESERVE_ROOT:
	  preserve_root = true;
	  break;

	case PRESUME_INPUT_TTY_OPTION:
	  x.stdin_tty = true;
	  break;

	case 'v':
	  x.verbose = true;
	  break;

	case_GETOPT_HELP_CHAR;
	case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
	default:
	  diagnose_leading_hyphen (argc, argv);
	  usage (EXIT_FAILURE);
	}
    }

  if (argc <= optind)
    {
      if (x.ignore_missing_files)
	exit (EXIT_SUCCESS);
      else
	{
	  error (0, 0, _("missing operand"));
	  usage (EXIT_FAILURE);
	}
    }

  if (x.recursive & preserve_root)
    {
      static struct dev_ino dev_ino_buf;
      x.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
      if (x.root_dev_ino == NULL)
	error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
	       quote ("/"));
    }

  {
    size_t n_files = argc - optind;
    char const *const *file = (char const *const *) argv + optind;

    if (prompt_once && (x.recursive || 3 < n_files))
      {
	fprintf (stderr,
		 (x.recursive
		  ? _("%s: remove all arguments recursively? ")
		  : _("%s: remove all arguments? ")),
		 program_name);
	if (!yesno ())
	  exit (EXIT_SUCCESS);
      }
    enum RM_status status = rm (n_files, file, &x);
    assert (VALID_STATUS (status));
    exit (status == RM_ERROR ? EXIT_FAILURE : EXIT_SUCCESS);
  }
}