cosmopolitan/libc/calls/tcdrain.c
2024-07-19 19:38:00 -07:00

74 lines
3.5 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 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/calls/cp.internal.h"
#include "libc/calls/internal.h"
#include "libc/intrin/fds.h"
#include "libc/calls/syscall-nt.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/calls/termios.h"
#include "libc/dce.h"
#include "libc/intrin/strace.h"
#include "libc/nt/files.h"
#include "libc/sysv/consts/termios.h"
#include "libc/sysv/errfuns.h"
#define TCSBRK 0x5409 // linux
#define TIOCDRAIN 0x2000745e // xnu, freebsd, openbsd, netbsd
static dontinline textwindows int sys_tcdrain_nt(int fd) {
if (!sys_isatty(fd))
return -1; // ebadf, enotty
// Tried FlushFileBuffers but it made Emacs hang when run in cmd.exe
// "Console output is not buffered." -Quoth MSDN on FlushFileBuffers
return 0;
}
/**
* Waits until all written output is transmitted.
*
* @param fd is file descriptor of tty
* @raise EBADF if `fd` isn't an open file descriptor
* @raise ENOTTY if `fd` is open but not a teletypewriter
* @raise EIO if process group of writer is orphaned, calling thread is
* not blocking `SIGTTOU`, and process isn't ignoring `SIGTTOU`
* @raise ECANCELED if thread was cancelled in masked mode
* @raise EINTR if signal was delivered
* @raise ENOSYS on bare metal
* @cancelationpoint
* @asyncsignalsafe
*/
int tcdrain(int fd) {
int rc;
BEGIN_CANCELATION_POINT;
if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
rc = enotty();
} else if (IsLinux()) {
rc = sys_ioctl_cp(fd, TCSBRK, (uintptr_t)1);
} else if (IsBsd()) {
rc = sys_ioctl_cp(fd, TIOCDRAIN, 0);
} else if (IsWindows()) {
rc = sys_tcdrain_nt(fd);
} else {
rc = enosys();
}
END_CANCELATION_POINT;
STRACE("tcdrain(%d) → %d% m", fd, rc);
return rc;
}