cosmopolitan/libc/stdio/vsscanf.c
Justine Tunney 68c7c9c1e0
Clean up some code
- Use good ELF technique in cosmo_dlopen()
- Make strerror() conform more to other libc impls
- Introduce __clear_cache() and use it in cosmo_dlopen()
- Remove libc/fmt/fmt.h header (trying to kill off LIBC_FMT)
2023-11-16 17:31:07 -08:00

51 lines
2.5 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 2020 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/dce.h"
#include "libc/fmt/internal.h"
struct StringScannerState {
const unsigned char *s;
size_t i;
};
static int vsscanfcb(void *arg) {
int res;
struct StringScannerState *state;
state = arg;
if ((res = state->s[state->i])) {
state->i++;
} else {
res = -1;
}
return res;
}
/**
* Decodes string.
*
* @see libc/fmt/vcscanf.h (for docs and implementation)
* @note to offer the best performance, we assume small codebases
* needing vsscanf() won't need sscanf() too; and as such, there's
* a small code size penalty to using both
*/
int vsscanf(const char *str, const char *fmt, va_list va) {
struct StringScannerState state = {(const unsigned char *)str, 0};
return __vcscanf(vsscanfcb, NULL, &state, fmt, va);
}