contrib/diffutils/lib/basename-lgpl.c

   1 /* basename.c -- return the last element in a file name
   2
   3    Copyright (C) 1990, 1998-2001, 2003-2006, 2009-2013 Free Software
   4    Foundation, Inc.
   5
   6    This program is free software: you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include <config.h>
  20
  21 #include "dirname.h"
  22
  23 #include <string.h>
  24
  25 /* Return the address of the last file name component of NAME.  If
  26    NAME has no relative file name components because it is a file
  27    system root, return the empty string.  */
  28
  29 char *
  30 last_component (char const *name)
  31 {
  32   char const *base = name + FILE_SYSTEM_PREFIX_LEN (name);
  33   char const *p;
  34   bool saw_slash = false;
  35
  36   while (ISSLASH (*base))
  37     base++;
  38
  39   for (p = base; *p; p++)
  40     {
  41       if (ISSLASH (*p))
  42         saw_slash = true;
  43       else if (saw_slash)
  44         {
  45           base = p;
  46           saw_slash = false;
  47         }
  48     }
  49
  50   return (char *) base;
  51 }
  52
  53 /* Return the length of the basename NAME.  Typically NAME is the
  54    value returned by base_name or last_component.  Act like strlen
  55    (NAME), except omit all trailing slashes.  */
  56
  57 size_t
  58 base_len (char const *name)
  59 {
  60   size_t len;
  61   size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
  62
  63   for (len = strlen (name);  1 < len && ISSLASH (name[len - 1]);  len--)
  64     continue;
  65
  66   if (DOUBLE_SLASH_IS_DISTINCT_ROOT && len == 1
  67       && ISSLASH (name[0]) && ISSLASH (name[1]) && ! name[2])
  68     return 2;
  69
  70   if (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE && prefix_len
  71       && len == prefix_len && ISSLASH (name[prefix_len]))
  72     return prefix_len + 1;
  73
  74   return len;
  75 }