char *to = strndup (arg, to_len);
char *to = __strndup (arg, to_len);
__argz_replace (char **argz, size_t *argz_len, const char *str, const char *with,		unsigned *replace_count){  error_t err = 0;  if (str && *str)    {      char *arg = 0;      char *src = *argz;      size_t src_len = *argz_len;      char *dst = 0;      size_t dst_len = 0;      int delayed_copy = 1;	/* True while we've avoided copying anything.  */      size_t str_len = strlen (str), with_len = strlen (with);      while (!err && (arg = argz_next (src, src_len, arg)))	{	  char *match = strstr (arg, str);	  if (match)	    {	      char *from = match + str_len;	      size_t to_len = match - arg;	      char *to = strndup (arg, to_len);	      while (to && from)		{		  str_append (&to, &to_len, with, with_len);		  if (to)		    {		      match = strstr (from, str);		      if (match)			{			  str_append (&to, &to_len, from, match - from);			  from = match + str_len;			}		      else			{			  str_append (&to, &to_len, from, strlen (from));			  from = 0;			}		    }		}	      if (to)		{		  if (delayed_copy)		    /* We avoided copying SRC to DST until we found a match;                       now that we've done so, copy everything from the start                       of SRC.  */		    {		      if (arg > src)			err = argz_append (&dst, &dst_len, src, (arg - src));		      delayed_copy = 0;		    }		  if (! err)		    err = argz_add (&dst, &dst_len, to);		  free (to);		}	      else		err = ENOMEM;	      if (replace_count)		(*replace_count)++;	    }	  else if (! delayed_copy)	    err = argz_add (&dst, &dst_len, arg);	}      if (! err)	{	  if (! delayed_copy)	    /* We never found any instances of str.  */	    {	      if (src)		free (src);	      *argz = dst;	      *argz_len = dst_len;	    }	}      else if (dst_len > 0)	free (dst);    }  return err;}