unlockpt - unlock a pseudoterminal master/slave pair

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ unlockpt()                                                                  │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

       The   unlockpt()   function   unlocks  the  slave  pseudoterminal  device  corresponding  to  the  master
       pseudoterminal referred to by the file descriptor fd.

       unlockpt() should be called before opening the slave side of a pseudoterminal.

EBADF  The fd argument is not a file descriptor open for writing.

       EINVAL The fd argument is not associated with a master pseudoterminal.

       glibc 2.1.  POSIX.1-2001.

       Standard C library (libc, -lc)

       unlockpt - unlock a pseudoterminal master/slave pair

       When successful, unlockpt() returns 0.  Otherwise, it returns -1 and sets errno to indicate the error.

grantpt(3), posix_openpt(3), ptsname(3), pts(4), pty(7)

Linux man-pages 6.9.1                              2024-05-02                                        unlockpt(3)

       POSIX.1-2008.

#define_XOPEN_SOURCE#include<stdlib.h>intunlockpt(intfd);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       unlockpt():
           Since glibc 2.24:
               _XOPEN_SOURCE >= 500
           glibc 2.23 and earlier:
               _XOPEN_SOURCE