posix_openpt(3) - NetBSD Manual Pages

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POSIX_OPENPT(3)         NetBSD Library Functions Manual        POSIX_OPENPT(3)


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

     posix_openpt() Searches for an unused master pseudo-terminal device,
     opens it, and returns a file descriptor associated the now used pseudo-
     terminal device.  The oflag argument has the same meaning as in the
     open(2) call.


RETURN VALUES

     If successful, posix_openpt() returns a non-negative integer, which cor-
     responds to a file descriptor pointing to the master pseudo-terminal
     device.  Otherwise, a value of -1 is returned and errno is set to indi-
     cate the error.


SEE ALSO

     ioctl(2), open(2), grantpt(3), ptsname(3), unlockpt(3)


RATIONALE

     The standards committee did not want to directly expose the cloning
     device, thus decided to wrap the functionality in this function.  The
     equivalent code would be:

             int
             posix_openpt(int oflag) {
                     return open("/dev/ptmx", oflag);
             }


STANDARDS

     The posix_openpt() function conforms to IEEE Std 1003.1-2001
     (``POSIX.1'').

NetBSD 5.1                       May 25, 2004                       NetBSD 5.1