src/basename.c

   1 /* basename -- strip directory and suffix from file names
   2    Copyright (C) 1990-2015 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 #include <config.h>
  18 #include <getopt.h>
  19 #include <stdio.h>
  20 #include <sys/types.h>
  21
  22 #include "system.h"
  23 #include "error.h"
  24 #include "quote.h"
  25
  26 /* The official name of this program (e.g., no 'g' prefix).  */
  27 #define PROGRAM_NAME "basename"
  28
  29 #define AUTHORS proper_name ("David MacKenzie")
  30
  31 static struct option const longopts[] =
  32 {
  33   {"multiple", no_argument, NULL, 'a'},
  34   {"suffix", required_argument, NULL, 's'},
  35   {"zero", no_argument, NULL, 'z'},
  36   {GETOPT_HELP_OPTION_DECL},
  37   {GETOPT_VERSION_OPTION_DECL},
  38   {NULL, 0, NULL, 0}
  39 };
  40
  41 void
  42 usage (int status)
  43 {
  44   if (status != EXIT_SUCCESS)
  45     emit_try_help ();
  46   else
  47     {
  48       printf (_("\
  49 Usage: %s NAME [SUFFIX]\n\
  50   or:  %s OPTION... NAME...\n\
  51 "),
  52               program_name, program_name);
  53       fputs (_("\
  54 Print NAME with any leading directory components removed.\n\
  55 If specified, also remove a trailing SUFFIX.\n\
  56 "), stdout);
  57
  58       emit_mandatory_arg_note ();
  59
  60       fputs (_("\
  61   -a, --multiple       support multiple arguments and treat each as a NAME\n\
  62   -s, --suffix=SUFFIX  remove a trailing SUFFIX; implies -a\n\
  63   -z, --zero           end each output line with NUL, not newline\n\
  64 "), stdout);
  65       fputs (HELP_OPTION_DESCRIPTION, stdout);
  66       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  67       printf (_("\
  68 \n\
  69 Examples:\n\
  70   %s /usr/bin/sort          -> \"sort\"\n\
  71   %s include/stdio.h .h     -> \"stdio\"\n\
  72   %s -s .h include/stdio.h  -> \"stdio\"\n\
  73   %s -a any/str1 any/str2   -> \"str1\" followed by \"str2\"\n\
  74 "),
  75               program_name, program_name, program_name, program_name);
  76       emit_ancillary_info (PROGRAM_NAME);
  77     }
  78   exit (status);
  79 }
  80
  81 /* Remove SUFFIX from the end of NAME if it is there, unless NAME
  82    consists entirely of SUFFIX.  */
  83
  84 static void
  85 remove_suffix (char *name, const char *suffix)
  86 {
  87   char *np;
  88   const char *sp;
  89
  90   np = name + strlen (name);
  91   sp = suffix + strlen (suffix);
  92
  93   while (np > name && sp > suffix)
  94     if (*--np != *--sp)
  95       return;
  96   if (np > name)
  97     *np = '\0';
  98 }
  99
 100 /* Perform the basename operation on STRING.  If SUFFIX is non-NULL, remove
 101    the trailing SUFFIX.  Finally, output the result string.  */
 102
 103 static void
 104 perform_basename (const char *string, const char *suffix, bool use_nuls)
 105 {
 106   char *name = base_name (string);
 107   strip_trailing_slashes (name);
 108
 109   /* Per POSIX, 'basename // /' must return '//' on platforms with
 110      distinct //.  On platforms with drive letters, this generalizes
 111      to making 'basename c: :' return 'c:'.  This rule is captured by
 112      skipping suffix stripping if base_name returned an absolute path
 113      or a drive letter (only possible if name is a file-system
 114      root).  */
 115   if (suffix && IS_RELATIVE_FILE_NAME (name) && ! FILE_SYSTEM_PREFIX_LEN (name))
 116     remove_suffix (name, suffix);
 117
 118   fputs (name, stdout);
 119   putchar (use_nuls ? '\0' : '\n');
 120   free (name);
 121 }
 122
 123 int
 124 main (int argc, char **argv)
 125 {
 126   bool multiple_names = false;
 127   bool use_nuls = false;
 128   const char *suffix = NULL;
 129
 130   initialize_main (&argc, &argv);
 131   set_program_name (argv[0]);
 132   setlocale (LC_ALL, "");
 133   bindtextdomain (PACKAGE, LOCALEDIR);
 134   textdomain (PACKAGE);
 135
 136   atexit (close_stdout);
 137
 138   while (true)
 139     {
 140       int c = getopt_long (argc, argv, "+as:z", longopts, NULL);
 141
 142       if (c == -1)
 143         break;
 144
 145       switch (c)
 146         {
 147         case 's':
 148           suffix = optarg;
 149           /* Fall through: -s implies -a.  */
 150
 151         case 'a':
 152           multiple_names = true;
 153           break;
 154
 155         case 'z':
 156           use_nuls = true;
 157           break;
 158
 159         case_GETOPT_HELP_CHAR;
 160         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 161
 162         default:
 163           usage (EXIT_FAILURE);
 164         }
 165     }
 166
 167   if (argc < optind + 1)
 168     {
 169       error (0, 0, _("missing operand"));
 170       usage (EXIT_FAILURE);
 171     }
 172
 173   if (!multiple_names && optind + 2 < argc)
 174     {
 175       error (0, 0, _("extra operand %s"), quote (argv[optind + 2]));
 176       usage (EXIT_FAILURE);
 177     }
 178
 179   if (multiple_names)
 180     {
 181       for (; optind < argc; optind++)
 182         perform_basename (argv[optind], suffix, use_nuls);
 183     }
 184   else
 185     perform_basename (argv[optind],
 186                       optind + 2 == argc ? argv[optind + 1] : NULL, use_nuls);
 187
 188   return EXIT_SUCCESS;
 189 }