src/kernel/lib/stdlib/atoi.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

#include <lib/math.h>
#include <lib/string.h>
#include <stddef.h>
#include <stdint.h>

int atoi(char *str)
{
	u32 s_str = strlen(str);
	if (!s_str)
		return 0;

	u8 negative = 0;
	if (str[0] == '-')
		negative = 1;

	u32 i = 0;
	if (negative)
		i++;

	int ret = 0;
	for (; i < s_str; i++) {
		ret += (str[i] - '0') * pow(10, (int)((s_str - i) - 1));
	}

	if (negative)
		ret *= -1;
	return ret;
}