Provided by: manpages-dev_2.17-1_all
unlockpt - unlock a pseudo-terminal master/slave pair
int unlockpt(int fd);
The unlockpt() function unlocks the slave pseudo-terminal device (pty)
corresponding to the master pty referred to by fd.
unlockpt() should be called before opening the slave side of a pty.
When successful, unlockpt() returns 0. Otherwise, it returns -1 and
sets errno appropriately.
EBADF The fd argument is not a file descriptor open for writing.
EINVAL The fd argument is not associated with a master pty.
grantpt(3), posix_openpt(3), ptsname(3), pts(4), pty(7)