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posix_openpt - open a pseudo-terminal device
int posix_openpt(int flags);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
posix_openpt(): _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
The posix_openpt() function opens an unused pseudo-terminal master
device, returning a file descriptor that can be used to refer to that
The flags argument is a bit mask that ORs together zero or more of the
O_RDWR Open the device for both reading and writing. It is usual to
specify this flag.
Do not make this device the controlling terminal for the
On success, posix_openpt() returns a non-negative file descriptor which
is the lowest numbered unused descriptor. On failure, -1 is returned,
and errno is set to indicate the error.
Glibc support for posix_openpt() has been provided since version 2.2.1.
posix_openpt() is part of the Unix98 pseudo-terminal support (see
pts(4)). This function is specified in POSIX.1-2001.
This function is a recent invention in POSIX. Some Unix
implementations that support System V (aka Unix 98) pseudo-terminals
don’t have this function, but it is easy to implement:
return open("/dev/ptmx", flags);
open(2), getpt(3), grantpt(3), ptsname(3), unlockpt(3), pts(4), pty(7)
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