status.i4.v = str_starts_with_c(string.i1a.r, length.i4.v,
					substring.i1a.r, substring_len.i4.v,
					direction.i4.v, options.u4.v)

	This routine determines whether or not a string starts (or ends)
	with a given substring.  Leading (or trailing) blanks will be

	string		string to search
	length		length of string to search (a value of zero
			will result in a search up to a null terminator)
	substring	substring to search for
	substring_len	length of substring to search for (If a value
			of zero is passed for this argument, the routine
			will determine the length of the substring.)
	direction	direction of search
			(STR_FIRST -> compare beginning of string,
			 STR_LAST -> compare end of string)
	options		compare options
			(STR_OPT_NONE -> no options selected,
			 STR_OPT_CASE_SENSITIVE -> case sensitive compare)

	This function returns status values as follows:

	CBS_INVARG		invalid length or direction passed
	FALSE			substring did not match
	otherwise		starting match position (starts at 1)

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	str_starts_with_char_type_c, str_find_first_c, str_get_first_c,
	str_nonblank_length_c, str_num_nonblank_c, str_is_blank_c, fndfst,
	str_find_character_c, str_find_character_set_c,
	str_find_not_in_character_set_c, fndchr(_c), str_find_string_c,
	str_find_last_string_c, strstr, strstr_nocase, str_insert_terminator_c,
	str_trim_c, str_trim_characters_c, str_character_count_c

	C/C++ usage:

	static const char	string[] = "   string   ";
	static const char	substring[] = "str";
	int	status;
	int	length = 0;
	int	substring_len = 0;
	int	direction = STR_FIRST;
	unsigned int	options = STR_OPT_NONE;

	status = str_starts_with_c(string,length,substring,substring_len,