view libutil/nanp_valid.c @ 274:de440a88c23a

doc/NANP-specifics: Fake-NANP-numbers article is here
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 27 Nov 2023 21:46:30 -0800
parents 81958b35f74d
children
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/*
 * Utility functions for NANP number validation.
 */

is_nanp_valid_prefix(s)
	char *s;
{
	/* validate NPA part */
	if (s[0] < '2')
		return(0);
	if (s[1] == '1' && s[2] == '1')
		return(0);
	/* validate exchange part */
	if (s[3] < '2')
		return(0);
	if (s[4] == '1' && s[5] == '1')
		return(0);
	/* all checks passed */
	return(1);
}