toolchain/gcc/newlib/libc/argz/argz_replace.c

   1 /* Copyright (C) 2002 by  Red Hat, Incorporated. All rights reserved.
   2  *
   3  * Permission to use, copy, modify, and distribute this software
   4  * is freely granted, provided that this notice is preserved.
   5  */
   6
   7 #include <errno.h>
   8 #include <sys/types.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11 #include <argz.h>
  12
  13 #include "buf_findstr.h"
  14
  15 error_t
  16 _DEFUN (argz_replace, (argz, argz_len, str, with, replace_count),
  17        char **argz _AND
  18        size_t *argz_len _AND
  19        const char *str _AND
  20        const char *with _AND
  21        unsigned *replace_count)
  22 {
  23   const int str_len = strlen(str);
  24   const int with_len = strlen(with);
  25   const int len_diff = with_len - str_len;
  26
  27   char *buf_iter = *argz;
  28   size_t buf_len = *argz_len;
  29   char *last_iter = NULL;
  30   char *new_argz = NULL;
  31   size_t new_argz_len = 0;
  32   char *new_argz_iter = NULL;
  33
  34   *replace_count = 0;
  35   new_argz_len = *argz_len;
  36
  37   while(buf_len)
  38     {
  39       if(_buf_findstr(str, &buf_iter, &buf_len))
  40         {
  41           *replace_count += 1;
  42           new_argz_len += len_diff;
  43         }
  44     }
  45
  46   if (*replace_count)
  47     {
  48       new_argz = (char *)malloc(new_argz_len);
  49
  50       buf_iter = *argz;
  51       buf_len = *argz_len;
  52       last_iter = buf_iter;
  53       new_argz_iter = new_argz;
  54
  55       while(buf_len)
  56         {
  57           if (_buf_findstr(str, &buf_iter, &buf_len))
  58             {
  59               /* copy everything up to, but not including str, from old argz to
  60                  new argz. */
  61               memcpy(new_argz_iter, last_iter, buf_iter - last_iter - str_len);
  62               new_argz_iter += (buf_iter - last_iter - str_len);
  63               /* copy replacement string. */
  64               memcpy(new_argz_iter, with, with_len);
  65               new_argz_iter += with_len;
  66               last_iter = buf_iter;
  67             }
  68         }
  69       /* copy everything after last occurrence of str. */
  70       memcpy(new_argz_iter, last_iter, *argz + *argz_len - last_iter);
  71
  72       /* reallocate argz, and copy over the new value. */
  73       if(!(*argz = (char *)realloc(*argz, new_argz_len)))
  74         return ENOMEM;
  75
  76       memcpy(*argz, new_argz, new_argz_len);
  77       *argz_len = new_argz_len;
  78
  79       if (*argz_len == 0)
  80         {
  81           free(*argz);
  82           *argz = NULL;
  83         }
  84       free(new_argz);
  85     }
  86
  87   return 0;
  88 }