basename

命令： basename

解释： 显示文件名

实现:

/* basename -- strip directory and suffix from file names
   Copyright (C) 1990-1997, 1999-2010 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 <http://www.gnu.org/licenses/>.  */

/* Usage: basename name [suffix]
   NAME is a file name; SUFFIX is a suffix to strip from it.

   basename /usr/foo/lossage/functions.l
   => functions.l
   basename /usr/foo/lossage/functions.l .l
   => functions
   basename functions.lisp p
   => functions.lis */

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

#include "system.h"
#include "long-options.h"
#include "error.h"
#include "quote.h"

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

#define AUTHORS proper_name ("David MacKenzie")

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
             program_name);
  else
    {
      printf (_("\
Usage: %s NAME [SUFFIX]\n\
  or:  %s OPTION\n\
"),
              program_name, program_name);
      fputs (_("\
Print NAME with any leading directory components removed.\n\
If specified, also remove a trailing SUFFIX.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      printf (_("\
\n\
Examples:\n\
  %s /usr/bin/sort       Output \"sort\".\n\
  %s include/stdio.h .h  Output \"stdio\".\n\
"),
              program_name, program_name);
      emit_ancillary_info ();
    }
  exit (status);
}

/* Remove SUFFIX from the end of NAME if it is there, unless NAME
   consists entirely of SUFFIX. */

static void
remove_suffix (char *name, const char *suffix)
{
  char *np;
  const char *sp;

  np = name + strlen (name);
  sp = suffix + strlen (suffix);

  while (np > name && sp > suffix)
    if (*--np != *--sp)
      return;
  if (np > name)
    *np = '\0';
}

int
main (int argc, char **argv)
{
  char *name;

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

  atexit (close_stdout);

  parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
                      usage, AUTHORS, (char const *) NULL);
  if (getopt_long (argc, argv, "+", NULL, NULL) != -1)
    usage (EXIT_FAILURE);

  if (argc < optind + 1)
    {
      error (0, 0, _("missing operand"));
      usage (EXIT_FAILURE);
    }

  if (optind + 2 < argc)
    {
      error (0, 0, _("extra operand %s"), quote (argv[optind + 2]));
      usage (EXIT_FAILURE);
    }

  name = base_name (argv[optind]);
  strip_trailing_slashes (name);

  /* Per POSIX, `basename // /' must return `//' on platforms with
     distinct //.  On platforms with drive letters, this generalizes
     to making `basename c: :' return `c:'.  This rule is captured by
     skipping suffix stripping if base_name returned an absolute path
     or a drive letter (only possible if name is a file-system
     root).  */
  if (argc == optind + 2 && IS_RELATIVE_FILE_NAME (name)
      && ! FILE_SYSTEM_PREFIX_LEN (name))
    remove_suffix (name, argv[optind + 1]);

  puts (name);
  free (name);

  exit (EXIT_SUCCESS);
}