lib/dirname.c

   1 /* dirname.c -- return all but the last element in a path
   2    Copyright (C) 1990, 1998, 2000, 2001, 2003 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 2, or (at your option)
   7    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, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 #if HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #include "dirname.h"
  23
  24 #include <string.h>
  25 #include "xalloc.h"
  26
  27 /* Return the length of `dirname (PATH)', or zero if PATH is
  28    in the working directory.  Works properly even if
  29    there are trailing slashes (by effectively ignoring them).  */
  30 size_t
  31 dir_len (char const *path)
  32 {
  33   size_t prefix_length = FILESYSTEM_PREFIX_LEN (path);
  34   size_t length;
  35
  36   /* Strip the basename and any redundant slashes before it.  */
  37   for (length = base_name (path) - path;  prefix_length < length;  length--)
  38     if (! ISSLASH (path[length - 1]))
  39       return length;
  40
  41   /* But don't strip the only slash from "/".  */
  42   return prefix_length + ISSLASH (path[prefix_length]);
  43 }
  44
  45 /* Return the leading directories part of PATH,
  46    allocated with xmalloc.
  47    Works properly even if there are trailing slashes
  48    (by effectively ignoring them).  */
  49
  50 char *
  51 dir_name (char const *path)
  52 {
  53   size_t length = dir_len (path);
  54   int append_dot = (length == FILESYSTEM_PREFIX_LEN (path));
  55   char *newpath = xmalloc (length + append_dot + 1);
  56   memcpy (newpath, path, length);
  57   if (append_dot)
  58     newpath[length++] = '.';
  59   newpath[length] = 0;
  60   return newpath;
  61 }
  62
  63 #ifdef TEST_DIRNAME
  64 /*
  65
  66 Run the test like this (expect no output):
  67   gcc -DHAVE_CONFIG_H -DTEST_DIRNAME -I.. -O -Wall \
  68      basename.c dirname.c xmalloc.c error.c
  69   sed -n '/^BEGIN-DATA$/,/^END-DATA$/p' dirname.c|grep -v DATA|./a.out
  70
  71 If it's been built on a DOS or Windows platforms, run another test like
  72 this (again, expect no output):
  73   sed -n '/^BEGIN-DOS-DATA$/,/^END-DOS-DATA$/p' dirname.c|grep -v DATA|./a.out
  74
  75 BEGIN-DATA
  76 foo//// .
  77 bar/foo//// bar
  78 foo/ .
  79 / /
  80 . .
  81 a .
  82 END-DATA
  83
  84 BEGIN-DOS-DATA
  85 c:///// c:/
  86 c:/ c:/
  87 c:/. c:/
  88 c:foo c:.
  89 c:foo/bar c:foo
  90 END-DOS-DATA
  91
  92 */
  93
  94 # define MAX_BUFF_LEN 1024
  95 # include <stdio.h>
  96
  97 char *program_name;
  98
  99 int
 100 main (int argc, char *argv[])
 101 {
 102   char buff[MAX_BUFF_LEN + 1];
 103
 104   program_name = argv[0];
 105
 106   buff[MAX_BUFF_LEN] = 0;
 107   while (fgets (buff, MAX_BUFF_LEN, stdin) && buff[0])
 108     {
 109       char path[MAX_BUFF_LEN];
 110       char expected_result[MAX_BUFF_LEN];
 111       char const *result;
 112       sscanf (buff, "%s %s", path, expected_result);
 113       result = dir_name (path);
 114       if (strcmp (result, expected_result))
 115         printf ("%s: got %s, expected %s\n", path, result, expected_result);
 116     }
 117   return 0;
 118 }
 119 #endif