cosmopolitan/libc/calls/vdprintf.c

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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/calls/internal.h"
#include "libc/dce.h"
#include "libc/fmt/fmt.h"
#include "libc/limits.h"
#include "libc/macros.h"
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#include "libc/nt/files.h"
#include "libc/sysv/errfuns.h"
struct VdprintfState {
int n;
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int fd;
unsigned char buf[1024];
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};
static int vdprintf_flush(struct VdprintfState *df, int n) {
int i, rc;
for (i = 0; i < n; i += rc) {
if ((rc = write(df->fd, df->buf + i, n - i)) == -1) {
return -1;
}
}
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return 0;
}
static int vdprintfputchar(int c, struct VdprintfState *df) {
df->buf[df->n++ & (ARRAYLEN(df->buf) - 1)] = c & 0xff;
if ((df->n & (ARRAYLEN(df->buf) - 1))) {
return 0;
} else {
return vdprintf_flush(df, ARRAYLEN(df->buf));
}
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}
/**
* Formats string directly to system i/o device.
*/
int(vdprintf)(int fd, const char *fmt, va_list va) {
struct VdprintfState df;
df.n = 0;
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df.fd = fd;
if (palandprintf(vdprintfputchar, &df, fmt, va) != -1 ||
vdprintf_flush(&df, df.n & (ARRAYLEN(df.buf) - 1)) != -1) {
return df.n;
} else {
return -1;
}
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}