usr/klibc/strntoumax.c

/*
 * strntoumax.c
 *
 * The strntoumax() function and associated
 */

#include <stddef.h>
#include <stdint.h>
#include <ctype.h>
#include <inttypes.h>

static inline int digitval(int ch)
{
	if (ch >= '0' && ch <= '9') {
		return ch - '0';
	} else if (ch >= 'A' && ch <= 'Z') {
		return ch - 'A' + 10;
	} else if (ch >= 'a' && ch <= 'z') {
		return ch - 'a' + 10;
	} else {
		return -1;
	}
}

uintmax_t strntoumax(const char *nptr, char **endptr, int base, size_t n)
{
	int minus = 0;
	uintmax_t v = 0;
	int d;

	while (n && isspace((unsigned char)*nptr)) {
		nptr++;
		n--;
	}

	/* Single optional + or - */
	if (n) {
		char c = *nptr;
		if (c == '-' || c == '+') {
			minus = (c == '-');
			nptr++;
			n--;
		}
	}

	if (base == 0) {
		if (n >= 2 && nptr[0] == '0' &&
		    (nptr[1] == 'x' || nptr[1] == 'X')) {
			n -= 2;
			nptr += 2;
			base = 16;
		} else if (n >= 1 && nptr[0] == '0') {
			n--;
			nptr++;
			base = 8;
		} else {
			base = 10;
		}
	} else if (base == 16) {
		if (n >= 2 && nptr[0] == '0' &&
		    (nptr[1] == 'x' || nptr[1] == 'X')) {
			n -= 2;
			nptr += 2;
		}
	}

	while (n && (d = digitval(*nptr)) >= 0 && d < base) {
		v = v * base + d;
		n--;
		nptr++;
	}

	if (endptr)
		*endptr = (char *)nptr;

	return minus ? -v : v;
}
1	/*
2	* strntoumax.c
3	*
4	* The strntoumax() function and associated
5	*/
6
7	#include <stddef.h>
8	#include <stdint.h>
9	#include <ctype.h>
10	#include <inttypes.h>
11
12	static inline int digitval(int ch)
13	{
14	if (ch >= '0' && ch <= '9') {
15	return ch - '0';
16	} else if (ch >= 'A' && ch <= 'Z') {
17	return ch - 'A' + 10;
18	} else if (ch >= 'a' && ch <= 'z') {
19	return ch - 'a' + 10;
20	} else {
21	return -1;
22	}
23	}
24
25	uintmax_t strntoumax(const char nptr, char *endptr, int base, size_t n)
26	{
27	int minus = 0;
28	uintmax_t v = 0;
29	int d;
30
31	while (n && isspace((unsigned char)*nptr)) {
32	nptr++;
33	n--;
34	}
35
36	/* Single optional + or - */
37	if (n) {
38	char c = *nptr;
39	if (c == '-' \|\| c == '+') {
40	minus = (c == '-');
41	nptr++;
42	n--;
43	}
44	}
45
46	if (base == 0) {
47	if (n >= 2 && nptr[0] == '0' &&
48	(nptr[1] == 'x' \|\| nptr[1] == 'X')) {
49	n -= 2;
50	nptr += 2;
51	base = 16;
52	} else if (n >= 1 && nptr[0] == '0') {
53	n--;
54	nptr++;
55	base = 8;
56	} else {
57	base = 10;
58	}
59	} else if (base == 16) {
60	if (n >= 2 && nptr[0] == '0' &&
61	(nptr[1] == 'x' \|\| nptr[1] == 'X')) {
62	n -= 2;
63	nptr += 2;
64	}
65	}
66
67	while (n && (d = digitval(*nptr)) >= 0 && d < base) {
68	v = v * base + d;
69	n--;
70	nptr++;
71	}
72
73	if (endptr)
74	endptr = (char )nptr;
75
76	return minus ? -v : v;
77	}