src/dirname.c

   1 /* dirname -- strip suffix from file name
   2
   3    Copyright (C) 1990-2024 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by David MacKenzie and Jim Meyering. */
  19
  20 #include <config.h>
  21 #include <getopt.h>
  22 #include <stdio.h>
  23 #include <sys/types.h>
  24
  25 #include "system.h"
  26
  27 /* The official name of this program (e.g., no 'g' prefix).  */
  28 #define PROGRAM_NAME "dirname"
  29
  30 #define AUTHORS \
  31   proper_name ("David MacKenzie"), \
  32   proper_name ("Jim Meyering")
  33
  34 static struct option const longopts[] =
  35 {
  36   {"zero", no_argument, nullptr, 'z'},
  37   {GETOPT_HELP_OPTION_DECL},
  38   {GETOPT_VERSION_OPTION_DECL},
  39   {nullptr, 0, nullptr, 0}
  40 };
  41
  42 void
  43 usage (int status)
  44 {
  45   if (status != EXIT_SUCCESS)
  46     emit_try_help ();
  47   else
  48     {
  49       printf (_("\
  50 Usage: %s [OPTION] NAME...\n\
  51 "),
  52               program_name);
  53       fputs (_("\
  54 Output each NAME with its last non-slash component and trailing slashes\n\
  55 removed; if NAME contains no /'s, output '.' (meaning the current directory).\n\
  56 \n\
  57 "), stdout);
  58       fputs (_("\
  59   -z, --zero     end each output line with NUL, not newline\n\
  60 "), stdout);
  61       fputs (HELP_OPTION_DESCRIPTION, stdout);
  62       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  63       printf (_("\
  64 \n\
  65 Examples:\n\
  66   %s /usr/bin/          -> \"/usr\"\n\
  67   %s dir1/str dir2/str  -> \"dir1\" followed by \"dir2\"\n\
  68   %s stdio.h            -> \".\"\n\
  69 "),
  70               program_name, program_name, program_name);
  71       emit_ancillary_info (PROGRAM_NAME);
  72     }
  73   exit (status);
  74 }
  75
  76 int
  77 main (int argc, char **argv)
  78 {
  79   static char const dot = '.';
  80   bool use_nuls = false;
  81   char const *result;
  82   size_t len;
  83
  84   initialize_main (&argc, &argv);
  85   set_program_name (argv[0]);
  86   setlocale (LC_ALL, "");
  87   bindtextdomain (PACKAGE, LOCALEDIR);
  88   textdomain (PACKAGE);
  89
  90   atexit (close_stdout);
  91
  92   while (true)
  93     {
  94       int c = getopt_long (argc, argv, "z", longopts, nullptr);
  95
  96       if (c == -1)
  97         break;
  98
  99       switch (c)
 100         {
 101         case 'z':
 102           use_nuls = true;
 103           break;
 104
 105         case_GETOPT_HELP_CHAR;
 106         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 107
 108         default:
 109           usage (EXIT_FAILURE);
 110         }
 111     }
 112
 113   if (argc < optind + 1)
 114     {
 115       error (0, 0, _("missing operand"));
 116       usage (EXIT_FAILURE);
 117     }
 118
 119   for (; optind < argc; optind++)
 120     {
 121       result = argv[optind];
 122       len = dir_len (result);
 123
 124       if (! len)
 125         {
 126           result = &dot;
 127           len = 1;
 128         }
 129
 130       fwrite (result, 1, len, stdout);
 131       putchar (use_nuls ? '\0' :'\n');
 132     }
 133
 134   return EXIT_SUCCESS;
 135 }