posix_openpt(3c) [opensolaris man page]

posix_openpt(3C)					   Standard C Library Functions 					  posix_openpt(3C)

NAME

       posix_openpt - open a pseudo terminal device

SYNOPSIS

       #include <stdlib.h>
       #include <fcntl.h>

       int posix_openpt(int oflag);

DESCRIPTION

       The posix_openpt() function establishes a connection between a master device for a pseudo-terminal and a file descriptor. The file descrip-
       tor is used by other I/O functions that refer to that pseudo-terminal.

       The file status flags and file access modes of the open file description are set according to the value of oflag.

       Values for oflag are constructed by a bitwise-inclusive OR of flags from the following list, defined in <fcntl.h>.

       O_RDWR	   Open for reading and writing.

       O_NOCTTY    If set, posix_openpt() does not cause the terminal device to become the controlling terminal for the process.

       The behavior of other values for the oflag argument is unspecified.

RETURN VALUES

       Upon successful completion, the posix_openpt() function opens a master pseudo-terminal device and returns a non-negative integer represent-
       ing the lowest numbered unused file descriptor. Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS

       The posix_openpt() function will fail if:

       EMFILE	 {OPEN_MAX} file descriptors are currently open in the calling process.

       ENFILE	 The maximum allowable number of files is currently open in the system.

       The posix_openpt() function may fail if:

       EINVAL	 The value of oflag is not valid.

       EAGAIN	 Out of pseudo-terminal resources.

       ENOSR	 Out of STREAMS resources.

EXAMPLES

       Example 1 Open a pseudo-terminal.

       The following example opens a pseudo-terminal and returns the name of the slave device and a file descriptor.

	 #include fcntl.h>
	 #include stdio.h>

	 int masterfd, slavefd;
	 char *slavedevice;

	 masterfd = posix_openpt(O_RDWR|O_NOCTTY);

	 if (masterfd == -1
	       || grantpt (masterfd) == -1
	       || unlockpt (masterfd) == -1
	       || (slavedevice = ptsname (masterfd)) == NULL)
	       return -1;

	 printf("slave device is: %s
", slavedevice);

	 slavefd = open(slave, O_RDWR|O_NOCTTY);
	 if (slavefd < 0)
	       return -1;

USAGE

       This function provieds a method for portably obtaining a file descriptor of a master terminal device for a pseudo-terminal. The grantpt(3C)
       and ptsname(3C) functions can be used to manipulate mode and ownership permissions and to obtain the name  of  the  slave  device,  respec-
       tively.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       open(2), grantpt(3C), ptsname(3C), unlockpt(3C), attributes(5), standards(5)

SunOS 5.11							    1 Dec  2003 						  posix_openpt(3C)

Check Out this Related Man Page

POSIX_OPENPT(2) 					      BSD System Calls Manual						   POSIX_OPENPT(2)

NAME

     posix_openpt -- open a pseudo-terminal device

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <stdlib.h>
     #include <fcntl.h>

     int
     posix_openpt(int oflag);

DESCRIPTION

     The posix_openpt() function allocates a new pseudo-terminal and establishes a connection with its master device.  A slave device shall be
     created in /dev/pts.  After the pseudo-terminal has been allocated, the slave device should have the proper permissions before it can be used
     (see grantpt(3)).	The name of the slave device can be determined by calling ptsname(3).

     The file status flags and file access modes of the open file description shall be set according to the value of oflag.  Values for oflag are
     constructed by a bitwise-inclusive OR of flags from the following list, defined in <fcntl.h>:

     O_RDWR	Open for reading and writing.

     O_NOCTTY	If set posix_openpt() shall not cause the terminal device to become the controlling terminal for the process.

     O_CLOEXEC	Set the close-on-exec flag for the new file descriptor.

     The posix_openpt() function shall fail when oflag contains other values.

RETURN VALUES

     Upon successful completion, the posix_openpt() function shall allocate a new pseudo-terminal device and return a non-negative integer repre-
     senting a file descriptor, which is connected to its master device.  Otherwise, -1 shall be returned and errno set to indicate the error.

ERRORS

     The posix_openpt() function shall fail if:

     [ENFILE]		The system file table is full.

     [EINVAL]		The value of oflag is not valid.

     [EAGAIN]		Out of pseudo-terminal resources.

SEE ALSO

     ptsname(3), pts(4), tty(4)

STANDARDS

     The posix_openpt() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').  The ability to use O_CLOEXEC is an extension to the standard.

HISTORY

     The posix_openpt() function appeared in FreeBSD 5.0.  In FreeBSD 8.0, this function was changed to a system call.

NOTES

     The flag O_NOCTTY is included for compatibility; in FreeBSD, opening a terminal does not cause it to become a process's controlling terminal.

AUTHORS

     Ed Schouten <ed@FreeBSD.org>

BSD
								  March 21, 2013							       BSD

Linux and UNIX Man Pages

posix_openpt(3c) [opensolaris man page]

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