source3/lib/string_init.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4
   5    Copyright (C) Andrew Tridgell 1992-2001
   6    Copyright (C) Simo Sorce      2001-2002
   7    Copyright (C) Martin Pool     2003
   8    Copyright (C) James Peach     2006
   9    Copyright (C) Jeremy Allison  1992-2007
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26
  27 /* this is used to prevent lots of mallocs of size 1 */
  28 static const char null_string[] = "";
  29
  30 /**
  31  Set a string value, allocing the space for the string
  32 **/
  33
  34 static bool string_init(char **dest,const char *src)
  35 {
  36         size_t l;
  37
  38         if (!src)
  39                 src = "";
  40
  41         l = strlen(src);
  42
  43         if (l == 0) {
  44                 *dest = discard_const_p(char, null_string);
  45         } else {
  46                 (*dest) = SMB_STRDUP(src);
  47                 if ((*dest) == NULL) {
  48                         DEBUG(0,("Out of memory in string_init\n"));
  49                         return false;
  50                 }
  51         }
  52         return(true);
  53 }
  54
  55 /**
  56  Free a string value.
  57 **/
  58
  59 void string_free(char **s)
  60 {
  61         if (!s || !(*s))
  62                 return;
  63         if (*s == null_string)
  64                 *s = NULL;
  65         SAFE_FREE(*s);
  66 }
  67
  68 /**
  69  Set a string value, deallocating any existing space, and allocing the space
  70  for the string
  71 **/
  72
  73 bool string_set(char **dest,const char *src)
  74 {
  75         string_free(dest);
  76         return(string_init(dest,src));
  77 }