glibc/sysvipc/ftok.c

35 lines
1.1 KiB
C

/* Copyright (C) 1995-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sys/ipc.h>
#include <sys/stat.h>
key_t
ftok (const char *pathname, int proj_id)
{
struct __stat64_t64 st;
key_t key;
if (__stat64_time64 (pathname, &st) < 0)
return (key_t) -1;
key = ((st.st_ino & 0xffff) | ((st.st_dev & 0xff) << 16)
| ((proj_id & 0xff) << 24));
return key;
}