src/basename.c

   1 /* basename -- strip directory and suffix from file names
   2    Copyright (C) 1990-1997, 1999-2011 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Usage: basename name [suffix]
  18    NAME is a file name; SUFFIX is a suffix to strip from it.
  19
  20    basename /usr/foo/lossage/functions.l
  21    => functions.l
  22    basename /usr/foo/lossage/functions.l .l
  23    => functions
  24    basename functions.lisp p
  25    => functions.lis */
  26
  27 #include <config.h>
  28 #include <getopt.h>
  29 #include <stdio.h>
  30 #include <sys/types.h>
  31
  32 #include "system.h"
  33 #include "long-options.h"
  34 #include "error.h"
  35 #include "quote.h"
  36
  37 /* The official name of this program (e.g., no `g' prefix).  */
  38 #define PROGRAM_NAME "basename"
  39
  40 #define AUTHORS proper_name ("David MacKenzie")
  41
  42 void
  43 usage (int status)
  44 {
  45   if (status != EXIT_SUCCESS)
  46     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  47              program_name);
  48   else
  49     {
  50       printf (_("\
  51 Usage: %s NAME [SUFFIX]\n\
  52   or:  %s OPTION\n\
  53 "),
  54               program_name, program_name);
  55       fputs (_("\
  56 Print NAME with any leading directory components removed.\n\
  57 If specified, also remove a trailing SUFFIX.\n\
  58 \n\
  59 "), stdout);
  60       fputs (HELP_OPTION_DESCRIPTION, stdout);
  61       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  62       printf (_("\
  63 \n\
  64 Examples:\n\
  65   %s /usr/bin/sort       Output \"sort\".\n\
  66   %s include/stdio.h .h  Output \"stdio\".\n\
  67 "),
  68               program_name, program_name);
  69       emit_ancillary_info ();
  70     }
  71   exit (status);
  72 }
  73
  74 /* Remove SUFFIX from the end of NAME if it is there, unless NAME
  75    consists entirely of SUFFIX. */
  76
  77 static void
  78 remove_suffix (char *name, const char *suffix)
  79 {
  80   char *np;
  81   const char *sp;
  82
  83   np = name + strlen (name);
  84   sp = suffix + strlen (suffix);
  85
  86   while (np > name && sp > suffix)
  87     if (*--np != *--sp)
  88       return;
  89   if (np > name)
  90     *np = '\0';
  91 }
  92
  93 int
  94 main (int argc, char **argv)
  95 {
  96   char *name;
  97
  98   initialize_main (&argc, &argv);
  99   set_program_name (argv[0]);
 100   setlocale (LC_ALL, "");
 101   bindtextdomain (PACKAGE, LOCALEDIR);
 102   textdomain (PACKAGE);
 103
 104   atexit (close_stdout);
 105
 106   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
 107                       usage, AUTHORS, (char const *) NULL);
 108   if (getopt_long (argc, argv, "+", NULL, NULL) != -1)
 109     usage (EXIT_FAILURE);
 110
 111   if (argc < optind + 1)
 112     {
 113       error (0, 0, _("missing operand"));
 114       usage (EXIT_FAILURE);
 115     }
 116
 117   if (optind + 2 < argc)
 118     {
 119       error (0, 0, _("extra operand %s"), quote (argv[optind + 2]));
 120       usage (EXIT_FAILURE);
 121     }
 122
 123   name = base_name (argv[optind]);
 124   strip_trailing_slashes (name);
 125
 126   /* Per POSIX, `basename // /' must return `//' on platforms with
 127      distinct //.  On platforms with drive letters, this generalizes
 128      to making `basename c: :' return `c:'.  This rule is captured by
 129      skipping suffix stripping if base_name returned an absolute path
 130      or a drive letter (only possible if name is a file-system
 131      root).  */
 132   if (argc == optind + 2 && IS_RELATIVE_FILE_NAME (name)
 133       && ! FILE_SYSTEM_PREFIX_LEN (name))
 134     remove_suffix (name, argv[optind + 1]);
 135
 136   puts (name);
 137   free (name);
 138
 139   exit (EXIT_SUCCESS);
 140 }