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94b7cc3711
fopen should set the FD_CLOEXEC flag if requested evenif the kernel does not support an aotmic operation. freopen should reuse the file descriptor for the stream. This is especially important for calls to change the standard streams (stin, stdout, stderr).
122 lines
3.6 KiB
C
122 lines
3.6 KiB
C
/* Copyright (C) 1993,95,96,97,98,2000,2001,2002,2003,2008,2011
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Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA.
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As a special exception, if you link the code in this file with
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files compiled with a GNU compiler to produce an executable,
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that does not cause the resulting executable to be covered by
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the GNU Lesser General Public License. This exception does not
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however invalidate any other reasons why the executable file
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might be covered by the GNU Lesser General Public License.
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This exception applies to code released by its copyright holders
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in files containing the exception. */
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#include "libioP.h"
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#include "stdio.h"
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#include <fcntl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <shlib-compat.h>
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#include <fd_to_filename.h>
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FILE*
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freopen (filename, mode, fp)
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const char* filename;
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const char* mode;
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FILE* fp;
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{
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FILE *result;
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CHECK_FILE (fp, NULL);
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if (!(fp->_flags & _IO_IS_FILEBUF))
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return NULL;
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_IO_acquire_lock (fp);
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int fd = _IO_fileno (fp);
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const char *gfilename = (filename == NULL && fd >= 0
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? fd_to_filename (fd) : filename);
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fp->_flags2 |= _IO_FLAGS2_NOCLOSE;
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#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
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if (&_IO_stdin_used == NULL)
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{
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/* If the shared C library is used by the application binary which
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was linked against the older version of libio, we just use the
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older one even for internal use to avoid trouble since a pointer
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to the old libio may be passed into shared C library and wind
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up here. */
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_IO_old_file_close_it (fp);
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_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_old_file_jumps;
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result = _IO_old_file_fopen (fp, gfilename, mode);
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}
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else
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#endif
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{
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INTUSE(_IO_file_close_it) (fp);
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_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps;
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if (_IO_vtable_offset (fp) == 0 && fp->_wide_data != NULL)
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fp->_wide_data->_wide_vtable = &_IO_wfile_jumps;
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result = INTUSE(_IO_file_fopen) (fp, gfilename, mode, 1);
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if (result != NULL)
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result = __fopen_maybe_mmap (result);
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}
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fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
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if (result != NULL)
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{
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/* unbound stream orientation */
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result->_mode = 0;
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if (fd != -1)
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{
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#ifdef O_CLOEXEC
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# ifndef __ASSUME_DUP3
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int newfd;
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if (__have_dup3 < 0)
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newfd = -1;
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else
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newfd =
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# endif
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dup3 (_IO_fileno (result), fd,
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(result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0
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? O_CLOEXEC : 0);
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#else
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# define newfd 1
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#endif
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#ifndef __ASSUME_DUP3
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if (newfd < 0)
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{
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if (errno == ENOSYS)
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__have_dup3 = -1;
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dup2 (_IO_fileno (result), fd);
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if ((result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0)
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__fcntl (fd, F_SETFD, FD_CLOEXEC);
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}
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#endif
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__close (_IO_fileno (result));
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_IO_fileno (result) = fd;
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}
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}
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else if (fd != -1)
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__close (fd);
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if (filename == NULL)
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free ((char *) gfilename);
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_IO_release_lock (fp);
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return result;
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}
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