X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fcloseout.c;h=5d0509dedecdb8c424ed72ec12dca757228c0517;hb=8de557e31178699dd6e839850056f0653cdfba89;hp=a4a986fa3f1a617e597923d03a0ce08a80105010;hpb=67f394c1d2be473276ccd5e071f986511a13e212;p=gnulib.git

diff --git a/lib/closeout.c b/lib/closeout.c
index a4a986fa3..5d0509ded 100644
--- a/lib/closeout.c
+++ b/lib/closeout.c
@@ -1,5 +1,7 @@
 /* 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
@@ -13,48 +15,87 @@
 
    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
+#ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
 
-#if ENABLE_NLS
-# include <libintl.h>
-# define _(Text) gettext (Text)
-#else
-# define _(Text) Text
-#endif
-
-#if 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);
+    }
 }