cosmopolitan/libc/fmt/formatoctal64.c
2022-04-29 06:10:10 -07:00

47 lines
2.3 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/fmt/itoa.h"
/**
* Converts unsigned 64-bit integer to octal string.
*
* @param p needs at least 24 bytes
* @param z ensures it starts with zero
* @return pointer to nul byte
*/
char *FormatOctal64(char p[hasatleast 24], uint64_t x, bool z) {
char t;
size_t i, a, b;
i = 0;
z = x && z;
do {
p[i++] = x % 8 + '0';
x = x / 8;
} while (x > 0);
if (z) p[i++] = '0';
p[i] = '\0';
if (i) {
for (a = 0, b = i - 1; a < b; ++a, --b) {
t = p[a];
p[a] = p[b];
p[b] = t;
}
}
return p + i;
}