1/* closeout.c - close standard output
2   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
3
4   This program is free software; you can redistribute it and/or modify
5   it under the terms of the GNU General Public License as published by
6   the Free Software Foundation; either version 2, or (at your option)
7   any later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program; if not, write to the Free Software Foundation,
16   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
17
18#if HAVE_CONFIG_H
19# include <config.h>
20#endif
21
22#if ENABLE_NLS
23# include <libintl.h>
24# define _(Text) gettext (Text)
25#else
26# define _(Text) Text
27#endif
28
29#if HAVE_STDLIB_H
30# include <stdlib.h>
31#endif
32#ifndef EXIT_FAILURE
33# define EXIT_FAILURE 1
34#endif
35
36#include <stdio.h>
37
38#include <errno.h>
39#ifndef errno
40extern int errno;
41#endif
42
43#include "closeout.h"
44#include "error.h"
45#include "quotearg.h"
46#if 0
47#include "__fpending.h"
48#endif
49
50static int default_exit_status = EXIT_FAILURE;
51static const char *file_name;
52
53/* Set the value to be used for the exit status when close_stdout is called.
54   This is useful when it is not convenient to call close_stdout_status,
55   e.g., when close_stdout is called via atexit.  */
56void
57close_stdout_set_status (int status)
58{
59  default_exit_status = status;
60}
61
62/* Set the file name to be reported in the event an error is detected
63   by close_stdout_status.  */
64void
65close_stdout_set_file_name (const char *file)
66{
67  file_name = file;
68}
69
70/* Close standard output, exiting with status STATUS on failure.
71   If a program writes *anything* to stdout, that program should `fflush'
72   stdout and make sure that it succeeds before exiting.  Otherwise,
73   suppose that you go to the extreme of checking the return status
74   of every function that does an explicit write to stdout.  The last
75   printf can succeed in writing to the internal stream buffer, and yet
76   the fclose(stdout) could still fail (due e.g., to a disk full error)
77   when it tries to write out that buffered data.  Thus, you would be
78   left with an incomplete output file and the offending program would
79   exit successfully.
80
81   FIXME: note the fflush suggested above is implicit in the fclose
82   we actually do below.  Consider doing only the fflush and/or using
83   setvbuf to inhibit buffering.
84
85   Besides, it's wasteful to check the return value from every call
86   that writes to stdout -- just let the internal stream state record
87   the failure.  That's what the ferror test is checking below.
88
89   It's important to detect such failures and exit nonzero because many
90   tools (most notably `make' and other build-management systems) depend
91   on being able to detect failure in other tools via their exit status.  */
92
93void
94close_stdout_status (int status)
95{
96  int e = ferror (stdout) ? 0 : -1;
97
98#if 0
99  if (__fpending (stdout) == 0)
100    return;
101#endif
102
103  if (fclose (stdout) != 0)
104    e = errno;
105
106  if (0 < e)
107    {
108      char const *write_error = _("write error");
109      if (file_name)
110	error (status, e, "%s: %s", quotearg_colon (file_name), write_error);
111      else
112	error (status, e, "%s", write_error);
113    }
114}
115
116/* Close standard output, exiting with status EXIT_FAILURE on failure.  */
117void
118close_stdout (void)
119{
120  close_stdout_status (default_exit_status);
121}
122