1/*
2 * atolfp - convert an ascii string to an l_fp number
3 */
4#include <config.h>
5#include <stdio.h>
6#include <ctype.h>
7
8#include "ntp_fp.h"
9#include "ntp_string.h"
10#include "ntp_assert.h"
11
12/*
13 * Powers of 10
14 */
15static u_long ten_to_the_n[10] = {
16	0,
17	10,
18	100,
19	1000,
20	10000,
21	100000,
22	1000000,
23	10000000,
24	100000000,
25	1000000000,
26};
27
28
29int
30atolfp(
31	const char *str,
32	l_fp *lfp
33	)
34{
35	register const char *cp;
36	register u_long dec_i;
37	register u_long dec_f;
38	char *ind;
39	int ndec;
40	int isneg;
41	static const char *digits = "0123456789";
42
43	REQUIRE(str != NULL);
44
45	isneg = 0;
46	dec_i = dec_f = 0;
47	ndec = 0;
48	cp = str;
49
50	/*
51	 * We understand numbers of the form:
52	 *
53	 * [spaces][-|+][digits][.][digits][spaces|\n|\0]
54	 */
55	while (isspace((unsigned char)*cp))
56	    cp++;
57
58	if (*cp == '-') {
59		cp++;
60		isneg = 1;
61	}
62
63	if (*cp == '+')
64	    cp++;
65
66	if (*cp != '.' && !isdigit((unsigned char)*cp))
67	    return 0;
68
69	while (*cp != '\0' && (ind = strchr(digits, *cp)) != NULL) {
70		dec_i = (dec_i << 3) + (dec_i << 1);	/* multiply by 10 */
71		dec_i += (u_long)(ind - digits);
72		cp++;
73	}
74
75	if (*cp != '\0' && !isspace((unsigned char)*cp)) {
76		if (*cp++ != '.')
77		    return 0;
78
79		while (ndec < 9 && *cp != '\0'
80		       && (ind = strchr(digits, *cp)) != NULL) {
81			ndec++;
82			dec_f = (dec_f << 3) + (dec_f << 1);	/* *10 */
83			dec_f += (u_long)(ind - digits);
84			cp++;
85		}
86
87		while (isdigit((unsigned char)*cp))
88		    cp++;
89
90		if (*cp != '\0' && !isspace((unsigned char)*cp))
91		    return 0;
92	}
93
94	if (ndec > 0) {
95		register u_long tmp;
96		register u_long bit;
97		register u_long ten_fact;
98
99		ten_fact = ten_to_the_n[ndec];
100
101		tmp = 0;
102		bit = 0x80000000;
103		while (bit != 0) {
104			dec_f <<= 1;
105			if (dec_f >= ten_fact) {
106				tmp |= bit;
107				dec_f -= ten_fact;
108			}
109			bit >>= 1;
110		}
111		if ((dec_f << 1) > ten_fact)
112		    tmp++;
113		dec_f = tmp;
114	}
115
116	if (isneg)
117	    M_NEG(dec_i, dec_f);
118
119	lfp->l_ui = dec_i;
120	lfp->l_uf = dec_f;
121	return 1;
122}
123