1/* Copyright (C) 1995-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <sys/ipc.h>
19#include <sys/stat.h>
20
21key_t
22ftok (const char *pathname, int proj_id)
23{
24 struct __stat64_t64 st;
25 key_t key;
26
27 if (__stat64_time64 (pathname, &st) < 0)
28 return (key_t) -1;
29
30 key = ((st.st_ino & 0xffff) | ((st.st_dev & 0xff) << 16)
31 | ((proj_id & 0xff) << 24));
32
33 return key;
34}
35

source code of glibc/sysvipc/ftok.c