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glibc  2.9
makedev.c
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00001 /* Definitions of functions to access `dev_t' values.
00002    Copyright (C) 2003 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <endian.h>
00021 #include <sys/sysmacros.h>
00022 
00023 unsigned int
00024 gnu_dev_major (unsigned long long int dev)
00025 {
00026   return ((dev >> 8) & 0xfff) | ((unsigned int) (dev >> 32) & ~0xfff);
00027 }
00028 
00029 unsigned int
00030 gnu_dev_minor (unsigned long long int dev)
00031 {
00032   return (dev & 0xff) | ((unsigned int) (dev >> 12) & ~0xff);
00033 }
00034 
00035 unsigned long long int
00036 gnu_dev_makedev (unsigned int major, unsigned int minor)
00037 {
00038   return ((minor & 0xff) | ((major & 0xfff) << 8)
00039          | (((unsigned long long int) (minor & ~0xff)) << 12)
00040          | (((unsigned long long int) (major & ~0xfff)) << 32));
00041 }