Function header_token

lib_acl_cpp/src/mime/internal/header_token.cpp:110–272

/* header_token - parse out the next item in a message header */

ssize_t header_token(HEADER_TOKEN *token, ssize_t token_len,
	ACL_VSTRING *token_buffer, const char **ptr,
	const char *user_specials, int user_terminator)
{
	ssize_t comment_level;
	const unsigned char *cp;
	ssize_t len;
	int     ch;
	ssize_t tok_count;
	ssize_t n;

	/*
	 * Initialize.
	 */
	ACL_VSTRING_RESET(token_buffer);
	cp = CU_CHAR_PTR(*ptr);
	tok_count = 0;
	if (user_specials == 0)
		user_specials = LEX_822_SPECIALS;

	/*
	 * Main parsing loop.
	 * 
	 * XXX What was the reason to continue parsing when user_terminator is
	 * specified? Perhaps this was needed at some intermediate stage of
	 * development?
	 */
	while ((ch = *cp) != 0 && (user_terminator != 0 || tok_count < token_len)) {
		cp++;

		/*
		 * Skip RFC 822 linear white space.
		 */
		if (IS_SPACE_TAB_CR_LF(ch))
			continue;

		/*
		 * Terminator.
		 */
		if (ch == user_terminator)
			break;

		/*
		 * Skip RFC 822 comment.
		 */
		if (ch == '(') {
			comment_level = 1;
			while ((ch = *cp) != 0) {
				cp++;
				if (ch == '(') {  /* comments can nest! */
					comment_level++;
				} else if (ch == ')') {
					if (--comment_level == 0)
						break;
				} else if (ch == '\\') {
					if ((ch = *cp) == 0)
						break;
					cp++;