+++ /dev/null
-/* Close standard input, rewinding seekable stdin if necessary.
-
- Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc.
-
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
-
- This program 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 General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
-
-#include <config.h>
-
-#include "closein.h"
-
-#include <errno.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <unistd.h>
-
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-
-#include "close-stream.h"
-#include "closeout.h"
-#include "error.h"
-#include "exitfail.h"
-#include "freadahead.h"
-#include "quotearg.h"
-
-static const char *file_name;
-
-/* Set the file name to be reported in the event an error is detected
- on stdin by close_stdin. See also close_stdout_set_file_name, if
- an error is detected when closing stdout. */
-void
-close_stdin_set_file_name (const char *file)
-{
- file_name = file;
-}
-
-/* Close standard input, rewinding any unused input if stdin is
- seekable. On error, issue a diagnostic and _exit with status
- 'exit_failure'. Then call close_stdout.
-
- Most programs can get by with close_stdout. close_stdin is only
- needed when a program wants to guarantee that partially read input
- from seekable stdin is not consumed, for any subsequent clients.
- For example, POSIX requires that these two commands behave alike:
-
- (sed -ne 1q; cat) < file
- tail -n +2 file
-
- Since close_stdin is commonly registered via 'atexit', POSIX
- and the C standard both say that it should not call 'exit',
- because the behavior is undefined if 'exit' is called more than
- once. So it calls '_exit' instead of 'exit'. If close_stdin
- is registered via atexit before other functions are registered,
- the other functions can act before this _exit is invoked.
-
- Applications that use close_stdout should flush any streams other
- than stdin, stdout, and stderr before exiting, since the call to
- _exit will bypass other buffer flushing. Applications should be
- flushing and closing other streams anyway, to check for I/O errors.
- Also, applications should not use tmpfile, since _exit can bypass
- the removal of these files.
-
- It's important to detect such failures and exit nonzero because many
- tools (most notably 'make' and other build-management systems) depend
- on being able to detect failure in other tools via their exit status. */
-
-void
-close_stdin (void)
-{
- bool fail = false;
-
- /* There is no need to flush stdin if we can determine quickly that stdin's
- input buffer is empty; in this case we know that if stdin is seekable,
- (fseeko (stdin, 0, SEEK_CUR), ftello (stdin))
- == lseek (0, 0, SEEK_CUR). */
- if (freadahead (stdin) > 0)
- {
- /* Only attempt flush if stdin is seekable, as fflush is entitled to
- fail on non-seekable streams. */
- if (fseeko (stdin, 0, SEEK_CUR) == 0 && fflush (stdin) != 0)
- fail = true;
- }
- if (close_stream (stdin) != 0)
- fail = true;
- if (fail)
- {
- /* Report failure, but defer exit until after closing stdout,
- since the failure report should still be flushed. */
- char const *close_error = _("error closing file");
- if (file_name)
- error (0, errno, "%s: %s", quotearg_colon (file_name),
- close_error);
- else
- error (0, errno, "%s", close_error);
- }
-
- close_stdout ();
-
- if (fail)
- _exit (exit_failure);
-}
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