cosmopolitan/libc/x/xbarf.c

66 lines
2.9 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 │
│ │
│ 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/calls.h"
#include "libc/errno.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/madv.h"
#include "libc/sysv/consts/o.h"
/**
* Writes data to file.
*
* @param size can be -1 to strlen(data)
* @return if failed, -1 w/ errno
* @note this is uninterruptible
*/
int xbarf(const char *path, const void *data, size_t size) {
char *p;
ssize_t rc;
int fd, res;
size_t i, wrote;
res = 0;
p = data;
if (size == -1) size = strlen(p);
if ((fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644)) != -1) {
if (ftruncate(fd, size) != -1) {
if (size > 2 * 1024 * 1024) {
fadvise(fd, 0, size, MADV_SEQUENTIAL);
}
for (i = 0; i < size; i += wrote) {
TryAgain:
if ((rc = pwrite(fd, p + i, size - i, i)) != -1) {
wrote = rc;
} else if (errno == EINTR) {
goto TryAgain;
} else {
res = -1;
break;
}
}
} else {
res = -1;
}
close(fd);
} else {
res = -1;
}
return res;
}