shmdt(2)                                                       shmdt(2)

  shmdt()

  NAME

    shmdt() - detach shared memory segment

  SYNOPSIS

    #include 

    int shmdt(const void *shmaddr)

  DESCRIPTION

    The shmdt(2) function detaches the shared memory segment at shmaddr from
    the address space of the calling process.

    The function parameters are:

    shmaddr
        a pointer to a shared memory segment.

    To delete a shared memory segment, use shmctl(2).

    The header file  includes .

  RETURN VALUE

    On success, the shmdt(2) function returns 0 and decrements the value of
    shm_nattach in the data structure associated with the shared memory
    segment.

    On failure, the function return s-1 and sets errno

  ERRORS

    The shmdt(2) function can fail for the following reasons:

    [EINVAL]
        Shmaddr does not point to the start of a data segment for a shared
        memory segment.

    [ENOSYS]
        The function isn't implemented.

  SEE ALSO

    shmat(2)

    shmctl(2)

    shmget(2)

  USAGE NOTES

    The shmdt function is thread safe.

    The shmdt function is not async-signal safe.