unlockpt
—
unlock the slave pseudo-terminal device
Standard C Library (libc, -lc)
#include <stdlib.h>
int
unlockpt
(int
fildes);
The unlockpt
() unlocks access to the pseudo-terminal
device corresponding to the master pseudo-terminal device associated with
fildes. Conforming applications must call this function
before opening the slave pseudo-terminal device.
If successful, unlockpt
() returns 0; otherwise a value
of -1 is returned and errno is set to indicate the
error.
The unlockpt
() function will fail if:
- [
EACCESS
]
- the corresponding pseudo-terminal device could not be accessed.
- [
EBADF
]
- fildes is not a valid descriptor.
- [
EINVAL
]
- fildes is not associated with a master
pseudo-terminal device.
In NetBSD unlockpt
() does
nothing.
The unlockpt
() function conforms to
IEEE Std 1003.1-2001 (“POSIX.1”). Its
first release was in X/Open Portability Guide Issue 4,
Version 2 (“XPG4.2”).