|PTSNAME(3)||Library Functions Manual||PTSNAME(3)|
unlockpt() functions allow access to pseudo-terminal devices. These three functions accept a file descriptor that references the master half of a pseudo-terminal pair. This file descriptor is created with posix_openpt(3).
grantpt() function is used to
establish ownership and permissions of the slave device counterpart to the
master device specified with fildes. The slave
device's ownership is set to the real user ID of the calling process, and
the permissions are set to user readable-writable and group writable. The
group owner of the slave device is also set to the group
ptsname() function returns the full
path name of the slave device counterpart to the master device specified
with fildes. This value can be used to subsequently
open the appropriate slave after
grantpt() have been called.
unlockpt() function clears the lock
held on the pseudo-terminal pair for the master device specified with
unlockpt() functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
ptsname() function returns a pointer
to the name of the slave device on success; otherwise a
NULL pointer is returned.
unlockpt() functions may fail and set errno to:
In addition, the
grantpt() function may
set errno to:
ptsname() function conforms to IEEE Std 1003.1-2008 (“POSIX.1”).
This implementation of
unlockpt() does not conform to IEEE
Std 1003.1-2008 (“POSIX.1”), because it depends on
posix_openpt(3) to create the
pseudo-terminal device with proper permissions in place. It only validates
whether fildes is a valid pseudo-terminal master
device. Future revisions of the specification will likely allow this
behaviour, as stated by the Austin Group.
unlockpt() functions appeared in OpenBSD 5.3.
|December 4, 2012||OpenBSD-current|