cosmopolitan/libc/calls/writev.c

55 lines
3.1 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/bits/weaken.h"
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/sock/internal.h"
#include "libc/sysv/errfuns.h"
#include "libc/zipos/zipos.internal.h"
/**
* Writes data from multiple buffers.
*
* Please note that it's not an error for a short write to happen. This
* can happen in the kernel if EINTR happens after some of the write has
* been committed. It can also happen if we need to polyfill this system
* call using write().
*
* @return number of bytes actually handed off, or -1 w/ errno
*/
ssize_t writev(int fd, const struct iovec *iov, int iovlen) {
if (fd < 0) return einval();
if (iovlen < 0) return einval();
if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
return weaken(__zipos_write)(
(struct ZiposHandle *)(intptr_t)g_fds.p[fd].handle, iov, iovlen, -1);
} else if (fd < g_fds.n && g_fds.p[fd].kind == kFdSerial) {
return writev$serial(&g_fds.p[fd], iov, iovlen);
} else if (!IsWindows()) {
return writev$sysv(fd, iov, iovlen);
} else if (fd < g_fds.n &&
(g_fds.p[fd].kind == kFdFile || g_fds.p[fd].kind == kFdConsole)) {
return write$nt(&g_fds.p[fd], iov, iovlen, -1);
} else if (fd < g_fds.n && g_fds.p[fd].kind == kFdSocket) {
return weaken(sendto$nt)(&g_fds.p[fd], iov, iovlen, 0, NULL, 0);
} else {
return ebadf();
}
}