cosmopolitan/libc/calls/posix_openpt.c

57 lines
2.8 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/calls/internal.h"
#include "libc/calls/termios.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/pty.h"
#include "libc/sysv/consts/termios.h"
#include "libc/sysv/errfuns.h"
/**
* Opens new pseudo teletypewriter.
*
* @params flags is usually O_RDWR|O_NOCTTY
* @return file descriptor, or -1 w/ errno
*/
int posix_openpt(int flags) {
int fd, ilduce;
struct IoctlPtmGet ptm;
if ((flags & O_ACCMODE) != O_RDWR) return einval();
if (SupportsFreebsd() &&
((fd = posix_openpt$sysv(flags)) != -1 || errno != ENOSYS)) {
return fd;
} else if ((fd = open("/dev/ptmx", flags)) != -1 || errno != ENOENT) {
return fd;
} else if (SupportsOpenbsd() &&
((fd = open("/dev/ptm", flags)) != -1 || errno != ENOENT)) {
if (ioctl(fd, PTMGET, &ptm) != -1) {
close(ptm.workerfd);
ilduce = ptm.theduxfd;
} else {
ilduce = -1;
}
close(fd);
return ilduce;
} else {
return enosys();
}
}