Function subst_str

re.c:592–652

! \return the substitution result in a str, input must be 0 term * 0 on no match or malloc error * if count is non zero it will be set to the number of matches, or -1 * if error */

 *   if error
 */
str* subst_str(const char *input, struct sip_msg* msg, struct subst_expr* se,
				int* count)
{
	str* res;
	struct replace_lst *lst;
	struct replace_lst* l;
	int len;
	int size;
	const char* p;
	char* dest;
	const char* end;


	/* compute the len */
	len=strlen(input);
	end=input+len;
	lst=subst_run(se, input, msg, count);
	if (lst==0){
		LM_DBG("no match\n");
		return 0;
	}
	for (l=lst; l; l=l->next)
		len+=(int)(l->rpl.len)-l->size;
	res=pkg_malloc(sizeof(str));
	if (res==0){
		LM_ERR("out of pkg memory\n");
		goto error;
	}
	res->s=pkg_malloc(len+1); /* space for null termination */
	if (res->s==0){
		LM_ERR("out of pkg memory (res->s)\n");
		goto error;
	}
	res->s[len]=0;
	res->len=len;

	/* replace */
	dest=res->s;
	p=input;
	for(l=lst; l; l=l->next){
		size=l->offset+input-p;
		memcpy(dest, p, size); /* copy till offset */
		p+=size + l->size; /* skip l->size bytes */
		dest+=size;
		if (l->rpl.len){
			memcpy(dest, l->rpl.s, l->rpl.len);
			dest+=l->rpl.len;
		}
	}
	memcpy(dest, p, end-p);
	if(lst) replace_lst_free(lst);
	return res;
error:
	if (lst) replace_lst_free(lst);
	if (res){
		if (res->s) pkg_free(res->s);
		pkg_free(res);
	}