lib/dirname.c

   1 /* dirname.c -- return all but the last element in a path
   2    Copyright 1990, 1998, 2000, 2001 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 #if STDC_HEADERS || HAVE_STRING_H
  23 # include <string.h>
  24 #endif
  25
  26 #include "dirname.h"
  27 #include "xalloc.h"
  28
  29 /* Return the length of `dirname (PATH)', or zero if PATH is
  30    in the working directory.  Works properly even if
  31    there are trailing slashes (by effectively ignoring them).  */
  32 size_t
  33 dir_len (char const *path)
  34 {
  35   size_t prefix_length = FILESYSTEM_PREFIX_LEN (path);
  36   size_t length;
  37
  38   /* Strip the basename and any redundant slashes before it.  */
  39   for (length = base_name (path) - path;  prefix_length < length;  length--)
  40     if (! ISSLASH (path[length - 1]))
  41       return length;
  42
  43   /* But don't strip the only slash from "/".  */
  44   return prefix_length + ISSLASH (path[prefix_length]);
  45 }
  46
  47 /* Return the leading directories part of PATH,
  48    allocated with xmalloc.
  49    Works properly even if there are trailing slashes
  50    (by effectively ignoring them).  */
  51
  52 char *
  53 dir_name (char const *path)
  54 {
  55   size_t length = dir_len (path);
  56   int append_dot = (length == FILESYSTEM_PREFIX_LEN (path));
  57   char *newpath = xmalloc (length + append_dot + 1);
  58   memcpy (newpath, path, length);
  59   if (append_dot)
  60     newpath[length++] = '.';
  61   newpath[length] = 0;
  62   return newpath;
  63 }
  64
  65 #ifdef TEST_DIRNAME
  66 /*
  67
  68 Run the test like this (expect no output):
  69   gcc -DHAVE_CONFIG_H -DTEST_DIRNAME -I.. -O -Wall \
  70      basename.c dirname.c xmalloc.c
  71   sed -n '/^BEGIN-DATA$/,/^END-DATA$/p' dirname.c|grep -v DATA|./a.out
  72
  73 BEGIN-DATA
  74 foo//// .
  75 bar/foo//// bar
  76 foo/ .
  77 / /
  78 . .
  79 a .
  80 END-DATA
  81
  82 */
  83
  84 # define MAX_BUFF_LEN 1024
  85 # include <stdio.h>
  86
  87 int
  88 main ()
  89 {
  90   char buff[MAX_BUFF_LEN + 1];
  91
  92   buff[MAX_BUFF_LEN] = 0;
  93   while (fgets (buff, MAX_BUFF_LEN, stdin) && buff[0])
  94     {
  95       char path[MAX_BUFF_LEN];
  96       char expected_result[MAX_BUFF_LEN];
  97       char const *result;
  98       sscanf (buff, "%s %s", path, expected_result);
  99       result = dir_name (path);
 100       if (strcmp (result, expected_result))
 101         printf ("%s: got %s, expected %s\n", path, result, expected_result);
 102     }
 103   return 0;
 104 }
 105 #endif