mirror of git://gcc.gnu.org/git/gcc.git
69 lines
2.1 KiB
C
69 lines
2.1 KiB
C
/* Compare two open file descriptors to see if they refer to the same file.
|
|
Copyright (C) 1991-2019 Free Software Foundation, Inc.
|
|
|
|
This file is part of the libiberty library.
|
|
Libiberty is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2 of the License, or (at your option) any later version.
|
|
|
|
Libiberty 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with libiberty; see the file COPYING.LIB. If
|
|
not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
|
|
Boston, MA 02110-1301, USA. */
|
|
|
|
|
|
/*
|
|
|
|
@deftypefn Extension int fdmatch (int @var{fd1}, int @var{fd2})
|
|
|
|
Check to see if two open file descriptors refer to the same file.
|
|
This is useful, for example, when we have an open file descriptor for
|
|
an unnamed file, and the name of a file that we believe to correspond
|
|
to that fd. This can happen when we are exec'd with an already open
|
|
file (@code{stdout} for example) or from the SVR4 @file{/proc} calls
|
|
that return open file descriptors for mapped address spaces. All we
|
|
have to do is open the file by name and check the two file descriptors
|
|
for a match, which is done by comparing major and minor device numbers
|
|
and inode numbers.
|
|
|
|
@end deftypefn
|
|
|
|
BUGS
|
|
|
|
(FIXME: does this work for networks?)
|
|
It works for NFS, which assigns a device number to each mount.
|
|
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
#include "ansidecl.h"
|
|
#include "libiberty.h"
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
|
|
int fdmatch (int fd1, int fd2)
|
|
{
|
|
struct stat sbuf1;
|
|
struct stat sbuf2;
|
|
|
|
if ((fstat (fd1, &sbuf1) == 0) &&
|
|
(fstat (fd2, &sbuf2) == 0) &&
|
|
(sbuf1.st_dev == sbuf2.st_dev) &&
|
|
(sbuf1.st_ino == sbuf2.st_ino))
|
|
{
|
|
return (1);
|
|
}
|
|
else
|
|
{
|
|
return (0);
|
|
}
|
|
}
|