svcadm(1M)을 검색하려면 섹션에서 1M 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
pts(4d)
Device Drivers & /dev files pts(4D)
NAME
pts - STREAMS pseudo-tty slave driver
DESCRIPTION
The pseudo-tty subsystem simulates a terminal connection, where the
master side represents the terminal and the slave represents the user
process's special device end point. The master device is set up as a
cloned device where its major device number is the major for the clone
device and its minor device number is the major for the ptm driver.
There are no nodes in the filesystem for master devices. The master
pseudo driver is opened using the open system call with /dev/ptmx as
the device parameter. For more information, see the open(2) man page.
The clone open finds the next available minor device for the ptm major
device. A master device is available only if it and its corresponding
slave device are not already open. When the master device is opened,
the corresponding slave device is automatically locked out. No user may
open that slave device until its permissions are adjusted and the
device unlocked by calling the functions grantpt() and unlockpt(). For
more information, see the grantpt(3C) and unlockpt(3C) man pages. The
user can then invoke the open system call with the name that is
returned by the ptsname() function. For more information, see the
ptsname(3C) man page. See the example below.
Only one open is allowed on a master device. Multiple opens are allowed
on the slave device. After both the master and slave have been opened,
the user has two file descriptors which are the end points of a full
duplex connection composed of two streams which are automatically con‐
nected at the master and slave drivers. The user may then push modules
onto either side of the stream pair. The autopush(8) system will push
the required STREAMS modules for terminal semantics on first open.
The master and slave drivers pass all messages to their adjacent
queues. Only the M_FLUSH needs some processing. Because the read queue
of one side is connected to the write queue of the other, the FLUSHR
flag is changed to the FLUSHW flag and vice versa. When the master
device is closed an M_HANGUP message is sent to the slave device which
will render the device unusable. The process on the slave side gets the
errno EIO when attempting to write on that stream but it will be able
to read any data remaining on the stream head read queue. When all the
data has been read, read returns 0 indicating that the stream can no
longer be used. On the last close of the slave device, a 0-length mes‐
sage is sent to the master device. When the application on the master
side issues a read() or getmsg() and 0 is returned, the user of the
master device decides whether to issue a close() that dismantles the
pseudo-terminal subsystem. If the master device is not closed, the
pseudo-tty subsystem will be available to another user to open the
slave device. Since 0-length messages are used to indicate that the
process on the slave side has closed and should be interpreted that way
by the process on the master side, applications on the slave side
should not write 0-length messages. If that occurs, the write returns
0, and the 0-length message is discarded by the ptem module.
The standard STREAMS system calls can access the pseudo-tty devices.
The slave devices support the O_NDELAY and O_NONBLOCK flags.
EXAMPLES
int fdm fds;
char *slavename;
extern char *ptsname();
fdm = open("/dev/ptmx", O_RDWR); /* open master */
grantpt(fdm); /* change permission of slave */
unlockpt(fdm); /* unlock slave */
slavename = ptsname(fdm); /* get name of slave */
fds = open(slavename, O_RDWR); /* open slave */
FILES
/dev/ptmx master clone device
/dev/pts/N slave devices (N = 1 -> number of ptys available)
SEE ALSO
ptsname(3C), unlockpt(3C), grantpt(3C), openpty(3C), posix_openpt(3C),
ptm(4D), ldterm(4M), ptem(4M), ttcompat(4M), autopush(8)
STREAMS Programming Guide
Oracle Solaris 11.4 Tunable Parameters Reference Manual
HISTORY
Prior to Oracle Solaris 11.4, the user needed to push the ptem and
ldterm modules onto the slave side of the pseudo-terminal subsystem to
get terminal semantics, and the ttcompat module on the slave side for
BSD compatibility ioctl calls, but only if open() was called from a
program not linked for XPG4 or later standards. If called from a pro‐
gram linked with values-xpg4.o or values-xpg6.o, then open() would
automatically push ptem, ldterm, and ttcompat modules onto the slave
side, and callers pushing them as well would encounter unexpected
behavior.
Oracle Solaris 11.4 added these modules to /etc/iu.system.ap so that
they are automatically pushed by autopush(8) regardless of how the pro‐
gram is linked, and ensured that only one copy of each is pushed onto
each stream.
Oracle Solaris 11.4 also added the openpty(3C) to encapsulate most of
this detail behind a portable interface.
Oracle Solaris 11.4 9 Jul 2018 pts(4D)