posix_openpt(3)

1POSIX_OPENPT(3)            Linux Programmer's Manual           POSIX_OPENPT(3)
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NAME

6       posix_openpt - open a pseudo-terminal device
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SYNOPSIS

9       #define _XOPEN_SOURCE 600
10       #include <stdlib.h>
11       #include <fcntl.h>
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13       int posix_openpt(int flags);
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DESCRIPTION

16       The  posix_openpt()  function  opens  an  unused pseudo-terminal master
17       device, returning a file descriptor that can be used to refer  to  that
18       device.
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20       The  flags argument is a bit mask that ORs together zero or more of the
21       following flags:
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23       O_RDWR Open the device for both reading and writing.  It  is  usual  to
24              specify this flag.
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26       O_NOCTTY
27              Do  not  make  this  device  the  controlling  terminal  for the
28              process.
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RETURN VALUE

31       On success, posix_openpt() returns a non-negative file descriptor which
32       is  the lowest numbered unused descriptor.  On failure, -1 is returned,
33       and errno is set to indicate the error.
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ERRORS

36       See open(2).
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CONFORMING TO

39       posix_openpt() is part  of  the  Unix98  pseudo-terminal  support  (see
40       pts(4)).  This function is specified in POSIX.1-2001.
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NOTES

43       This  function  is  a recent invention in POSIX.  Some Unix implementa‐
44       tions that support System V (aka Unix 98) pseudo-terminals  don't  have
45       this function, but it is easy to implement:
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47            int
48            posix_openpt(int flags)
49            {
50                return open("/dev/ptmx", flags);
51            }
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