65 lines
2.7 KiB
C
65 lines
2.7 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/conv/conv.h"
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#include "libc/str/str.h"
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/**
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* Decodes 128-bit unsigned integer from ASCII string.
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*
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* This is a more restricted form of strtoimax() that's useful for folks
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* needing to decode numbers in the range [1^127, 1^128).
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*/
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uintmax_t strtoumax(const char *s, char **endptr, int base) {
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const unsigned char *p = (const unsigned char *)s;
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uintmax_t res = 0;
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while (isspace(*p)) {
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p++;
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}
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if (!base) {
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if (*p == '0') {
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p++;
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if (*p == 'x' || *p == 'X') {
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p++;
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base = 16;
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} else if (*p == 'b' || *p == 'B') {
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p++;
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base = 2;
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} else {
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base = 8;
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}
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} else {
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base = 10;
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}
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}
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for (;;) {
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unsigned diglet = kBase36[*p];
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if (!diglet || diglet > base) break;
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p++;
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res *= base;
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res += diglet - 1;
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}
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if (endptr) *endptr = (char *)p;
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return res;
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}
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