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92 lines
2.5 KiB
C
92 lines
2.5 KiB
C
/* provide a replacement openat function
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Copyright (C) 2004 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* written by Jim Meyering */
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#include <config.h>
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#include "openat.h"
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#include <stdlib.h>
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#include <stdarg.h>
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#include <unistd.h>
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#include <errno.h>
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#include <fcntl.h>
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#include "error.h"
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#include "exitfail.h"
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#include "save-cwd.h"
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#include "gettext.h"
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#define _(msgid) gettext (msgid)
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/* Replacement for Solaris' openat function.
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<http://www.google.com/search?q=openat+site:docs.sun.com>
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Simulate it by doing save_cwd/fchdir/open/restore_cwd.
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If either the save_cwd or the restore_cwd fails (relatively unlikely,
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and usually indicative of a problem that deserves close attention),
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then give a diagnostic and exit nonzero.
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Otherwise, upon failure, set errno and return -1, as openat does.
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Upon successful completion, return a file descriptor. */
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int
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rpl_openat (int fd, char const *filename, int flags, ...)
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{
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struct saved_cwd saved_cwd;
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int saved_errno;
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int new_fd;
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mode_t mode = 0;
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if (flags & O_CREAT)
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{
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va_list arg;
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va_start (arg, flags);
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/* Assume that mode_t is passed compatibly with mode_t's type
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after argument promotion. */
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mode = va_arg (arg, mode_t);
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va_end (arg);
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}
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if (fd == AT_FDCWD || *filename == '/')
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return open (filename, flags, mode);
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if (save_cwd (&saved_cwd) != 0)
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error (exit_failure, errno,
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_("openat: unable to record current working directory"));
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if (fchdir (fd) != 0)
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{
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saved_errno = errno;
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free_cwd (&saved_cwd);
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errno = saved_errno;
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return -1;
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}
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new_fd = open (filename, flags, mode);
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saved_errno = errno;
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if (restore_cwd (&saved_cwd) != 0)
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error (exit_failure, errno,
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_("openat: unable to restore working directory"));
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free_cwd (&saved_cwd);
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errno = saved_errno;
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return new_fd;
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}
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