52 lines
2.6 KiB
C
52 lines
2.6 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/dce.h"
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#include "libc/fmt/fmt.h"
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struct StringScannerState {
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const unsigned char *s;
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size_t i;
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};
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static int vsscanfcb(void *arg) {
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int res;
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struct StringScannerState *state;
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state = arg;
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if ((res = state->s[state->i])) {
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state->i++;
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} else {
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res = -1;
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}
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return res;
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}
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/**
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* Decodes string.
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*
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* @see libc/fmt/vcscanf.h (for docs and implementation)
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* @note to offer the best performance, we assume small codebases
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* needing vsscanf() won't need sscanf() too; and as such, there's
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* a small code size penalty to using both
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*/
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int(vsscanf)(const char *str, const char *fmt, va_list va) {
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struct StringScannerState state = {(const unsigned char *)str, 0};
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return vcscanf(vsscanfcb, NULL, &state, fmt, va);
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}
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