40 lines
919 B
C++
40 lines
919 B
C++
/* ipc.cc: Single unix specification IPC interface for Cygwin
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Copyright 2001, 2002 Red Hat, Inc.
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Originally written by Robert Collins <robert.collins@hotmail.com>
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This file is part of Cygwin.
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This software is a copyrighted work licensed under the terms of the
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Cygwin license. Please consult the file "CYGWIN_LICENSE" for
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details. */
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#include "winsup.h"
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#include <cygwin/ipc.h>
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#include <sys/stat.h>
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extern "C"
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{
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/* Notes: we return a valid key even if id's low order 8 bits are 0. */
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key_t
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ftok (const char *path, int id)
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{
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struct stat statbuf;
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if (stat (path, &statbuf))
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{
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/* stat set the appropriate errno for us */
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return (key_t) -1;
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}
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/* dev_t is short for cygwin
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* ino_t is long for cygwin
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* and we need 8 bits for the id.
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* thus key_t is long long.
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*/
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return ((long long) statbuf.st_dev << (5*8)) | (statbuf.st_ino << (8) ) | (id & 0x00ff);
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}
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}
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