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use "syscall.zig";
pub const stdin_fileno : isize = 0;
pub const stdout_fileno : isize = 1;
pub const stderr_fileno : isize = 2;
// TODO error handling
pub fn os_get_random_bytes(buf: &u8, count: usize) isize => {
getrandom(buf, count, 0)
}
// TODO error handling
// TODO handle buffering and flushing (mutex protected)
pub fn print_str(str: []const u8) isize => {
fprint_str(stdout_fileno, str)
}
// TODO error handling
// TODO handle buffering and flushing (mutex protected)
pub fn fprint_str(fd: isize, str: []const u8) isize => {
write(fd, str.ptr, str.len)
}
// TODO handle buffering and flushing (mutex protected)
// TODO error handling
pub fn print_u64(x: u64) isize => {
var buf: [max_u64_base10_digits]u8;
const len = buf_print_u64(buf, x);
return write(stdout_fileno, buf.ptr, len);
}
// TODO handle buffering and flushing (mutex protected)
// TODO error handling
pub fn print_i64(x: i64) isize => {
var buf: [max_u64_base10_digits]u8;
const len = buf_print_i64(buf, x);
return write(stdout_fileno, buf.ptr, len);
}
// TODO error handling
pub fn readline(buf: []u8, out_len: &usize) bool => {
const amt_read = read(stdin_fileno, buf.ptr, buf.len);
if (amt_read < 0) {
return true;
}
*out_len = usize(amt_read);
return false;
}
// TODO return ?u64 when we support returning struct byval
pub fn parse_u64(buf: []u8, radix: u8, result: &u64) bool => {
var x : u64 = 0;
var i : @typeof(buf.len) = 0;
while (i < buf.len) {
const c = buf[i];
const digit = char_to_digit(c);
if (digit > radix) {
return true;
}
// x *= radix
if (@mul_with_overflow_u64(x, radix, &x)) {
return true;
}
// x += digit
if (@add_with_overflow_u64(x, digit, &x)) {
return true;
}
i += 1;
}
*result = x;
return false;
}
fn char_to_digit(c: u8) u8 => {
if ('0' <= c && c <= '9') {
c - '0'
} else if ('A' <= c && c <= 'Z') {
c - 'A' + 10
} else if ('a' <= c && c <= 'z') {
c - 'a' + 10
} else {
@max_value(u8)
}
}
const max_u64_base10_digits: usize = 20;
fn buf_print_i64(out_buf: []u8, x: i64) usize => {
if (x < 0) {
out_buf[0] = '-';
return 1 + buf_print_u64(out_buf[1...], u64(-(x + 1)) + 1);
} else {
return buf_print_u64(out_buf, u64(x));
}
}
fn buf_print_u64(out_buf: []u8, x: u64) usize => {
var buf: [max_u64_base10_digits]u8;
var a = x;
var index = buf.len;
while (true) {
const digit = a % 10;
index -= 1;
buf[index] = '0' + u8(digit);
a /= 10;
if (a == 0)
break;
}
const len = buf.len - index;
@memcpy(out_buf.ptr, &buf[index], len);
return len;
}
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