contrib/cpio/dirname.c

   1 /* dirname.c -- return all but the last element in a path
   2    Copyright (C) 1990 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
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include <config.h>
  20 #endif
  21
  22 #ifdef STDC_HEADERS
  23 #include <stdlib.h>
  24 #else
  25 char *malloc ();
  26 #endif
  27 #if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
  28 #include <string.h>
  29 #else
  30 #include <strings.h>
  31 #ifndef strrchr
  32 #define strrchr rindex
  33 #endif
  34 #endif
  35
  36 /* Return the leading directories part of PATH,
  37    allocated with malloc.  If out of memory, return 0.
  38    Assumes that trailing slashes have already been
  39    removed.  */
  40
  41 char *
  42 dirname (path)
  43      char *path;
  44 {
  45   char *newpath;
  46   char *slash;
  47   int length;                   /* Length of result, not including NUL.  */
  48
  49   slash = strrchr (path, '/');
  50   if (slash == 0)
  51     {
  52       /* File is in the current directory.  */
  53       path = ".";
  54       length = 1;
  55     }
  56   else
  57     {
  58       /* Remove any trailing slashes from the result.  */
  59       while (slash > path && *slash == '/')
  60         --slash;
  61
  62       length = slash - path + 1;
  63     }
  64   newpath = (char *) malloc (length + 1);
  65   if (newpath == 0)
  66     return 0;
  67   strncpy (newpath, path, length);
  68   newpath[length] = 0;
  69   return newpath;
  70 }