/* closeout.c - close standard output
- Copyright (C) 1998 Free Software Foundation, Inc.
+
+ Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 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
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
-#if ENABLE_NLS
-# include <libintl.h>
-# define _(Text) gettext (Text)
-#else
-# define _(Text) Text
-#endif
-
-#ifdef HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
-#ifndef EXIT_FAILURE
-# define EXIT_FAILURE 1
-#endif
+#include "closeout.h"
+#include <stdio.h>
+#include <stdbool.h>
#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
-#include <stdio.h>
-#include "closeout.h"
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
#include "error.h"
+#include "exitfail.h"
+#include "quotearg.h"
+#include "__fpending.h"
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
-/* Close standard output, exiting with status STATUS on failure. */
+static const char *file_name;
+
+/* Set the file name to be reported in the event an error is detected
+ by close_stdout. */
void
-close_stdout_status (int status)
+close_stdout_set_file_name (const char *file)
{
- if (ferror (stdout))
- error (status, 0, _("write error"));
- if (fclose (stdout) != 0)
- error (status, errno, _("write error"));
+ file_name = file;
}
-/* Close standard output, exiting with status EXIT_FAILURE on failure. */
+/* Close standard output, exiting with status 'exit_failure' on failure.
+ If a program writes *anything* to stdout, that program should close
+ stdout and make sure that it succeeds before exiting. Otherwise,
+ suppose that you go to the extreme of checking the return status
+ of every function that does an explicit write to stdout. The last
+ printf can succeed in writing to the internal stream buffer, and yet
+ the fclose(stdout) could still fail (due e.g., to a disk full error)
+ when it tries to write out that buffered data. Thus, you would be
+ left with an incomplete output file and the offending program would
+ exit successfully. Even calling fflush is not always sufficient,
+ since some file systems (NFS and CODA) buffer written/flushed data
+ until an actual close call.
+
+ Besides, it's wasteful to check the return value from every call
+ that writes to stdout -- just let the internal stream state record
+ the failure. That's what the ferror test is checking below.
+
+ 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_stdout (void)
{
- close_stdout_status (EXIT_FAILURE);
+ bool prev_fail = ferror (stdout);
+ bool none_pending = (0 == __fpending (stdout));
+ bool fclose_fail = fclose (stdout);
+
+ if (prev_fail || fclose_fail)
+ {
+ int e = fclose_fail ? errno : 0;
+ char const *write_error;
+
+ /* If ferror returned zero, no data remains to be flushed, and we'd
+ otherwise fail with EBADF due to a failed fclose, then assume that
+ it's ok to ignore the fclose failure. That can happen when a
+ program like cp is invoked like this `cp a b >&-' (i.e., with
+ stdout closed) and doesn't generate any output (hence no previous
+ error and nothing to be flushed). */
+ if (e == EBADF && !prev_fail && none_pending)
+ return;
+
+ write_error = _("write error");
+ if (file_name)
+ error (exit_failure, e, "%s: %s", quotearg_colon (file_name),
+ write_error);
+ else
+ error (exit_failure, e, "%s", write_error);
+ }
}