hextolfp.c revision 293894 
1163519Simp/*
2163519Simp * hextolfp - convert an ascii hex string to an l_fp number
3319182Sngie */
4163519Simp#include <config.h>
5163519Simp#include <stdio.h>
6318197Smarius#include <ctype.h>
7163519Simp
8163519Simp#include "ntp_fp.h"
9#include "ntp_string.h"
10#include "ntp_stdlib.h"
11
12int
13hextolfp(
14	const char *str,
15	l_fp *lfp
16	)
17{
18	register const char *cp;
19	register const char *cpstart;
20	register u_long dec_i;
21	register u_long dec_f;
22	char *ind = NULL;
23	static const char *digits = "0123456789abcdefABCDEF";
24
25	dec_i = dec_f = 0;
26	cp = str;
27
28	/*
29	 * We understand numbers of the form:
30	 *
31	 * [spaces]8_hex_digits[.]8_hex_digits[spaces|\n|\0]
32	 */
33	while (isspace((unsigned char)*cp))
34	    cp++;
35
36	cpstart = cp;
37	while (*cp != '\0' && (cp - cpstart) < 8 &&
38	       (ind = strchr(digits, *cp)) != NULL) {
39		dec_i = dec_i << 4;	/* multiply by 16 */
40		dec_i += ((ind - digits) > 15)
41			? (u_long)(ind - digits - 6)
42			: (u_long)(ind - digits);
43		cp++;
44	}
45
46	if ((cp - cpstart) < 8 || ind == NULL)
47	    return 0;
48	if (*cp == '.')
49	    cp++;
50
51	cpstart = cp;
52	while (*cp != '\0' && (cp - cpstart) < 8 &&
53	       (ind = strchr(digits, *cp)) != NULL) {
54		dec_f = dec_f << 4;	/* multiply by 16 */
55		dec_f += ((ind - digits) > 15)
56			? (u_long)(ind - digits - 6)
57			: (u_long)(ind - digits);
58		cp++;
59	}
60
61	if ((cp - cpstart) < 8 || ind == NULL)
62	    return 0;
63
64	if (*cp != '\0' && !isspace((unsigned char)*cp))
65	    return 0;
66
67	lfp->l_ui = dec_i;
68	lfp->l_uf = dec_f;
69	return 1;
70}
71