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glibc  2.9
getuid.c
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00001 /* Copyright (C) 2000, 2003, 2006 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <errno.h>
00020 #include <unistd.h>
00021 
00022 #include <sysdep.h>
00023 #include <sys/syscall.h>
00024 
00025 #include <kernel-features.h>
00026 
00027 #ifdef __NR_getuid32
00028 # if __ASSUME_32BITUIDS == 0
00029 /* This variable is shared with all files that need to check for 32bit
00030    uids.  This is the definition.
00031    -1 if libc does not know yet whether kernel has 32bit uids or not.
00032    0 if it does have them.
00033    1 if it does not have them.  */
00034 int __libc_missing_32bit_uids attribute_hidden = -1;
00035 # endif
00036 #endif /* __NR_getuid32 */
00037 
00038 uid_t
00039 __getuid (void)
00040 {
00041   INTERNAL_SYSCALL_DECL (err);
00042 #if __ASSUME_32BITUIDS > 0
00043   /* No error checking.  */
00044   return INTERNAL_SYSCALL (getuid32, err, 0);
00045 #else
00046 # ifdef __NR_getuid32
00047   if (__libc_missing_32bit_uids <= 0)
00048     {
00049       int result;
00050 
00051       result = INTERNAL_SYSCALL (getuid32, err, 0);
00052       if (! INTERNAL_SYSCALL_ERROR_P (result, err)
00053          || INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
00054        return result;
00055 
00056       __libc_missing_32bit_uids = 1;
00057     }
00058 # endif /* __NR_getuid32 */
00059 
00060   /* No error checking.  */
00061   return INTERNAL_SYSCALL (getuid, err, 0);
00062 #endif
00063 }
00064 
00065 weak_alias (__getuid, getuid)