unlockpt — unlock a pseudoterminal master/slave pair
int unlockpt(int fd);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
Since glibc 2.24:
_XOPEN_SOURCE >= 500 ||
(_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED)
Glibc 2.23 and earlier:
The unlockpt() function unlocks the slave pseudoterminal device corresponding to the master pseudoterminal referred to by fd.
unlockpt() should be called before opening the slave side of a pseudoterminal.
When successful, unlockpt() returns 0. Otherwise, it returns -1 and sets errno appropriately.
The fd argument is not a file descriptor open for writing.
The fd argument is not associated with a master pseudoterminal.
unlockpt() is provided in glibc since version 2.1.
For an explanation of the terms used in this section, see attributes(7).
grantpt(3), posix_openpt(3), ptsname(3), pts(4), pty(7)
This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
getpt(3), grantpt(3), ioctl_tty(2), posix_openpt(3), pts(4), ptsname(3), pty(7).