1 /* closeout.c - close standard output
3 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
30 #define _(msgid) gettext (msgid)
37 # include "unlocked-io.h"
40 static const char *file_name;
42 /* Set the file name to be reported in the event an error is detected
45 close_stdout_set_file_name (const char *file)
50 /* Close standard output, exiting with status 'exit_failure' on failure.
51 If a program writes *anything* to stdout, that program should close
52 stdout and make sure that it succeeds before exiting. Otherwise,
53 suppose that you go to the extreme of checking the return status
54 of every function that does an explicit write to stdout. The last
55 printf can succeed in writing to the internal stream buffer, and yet
56 the fclose(stdout) could still fail (due e.g., to a disk full error)
57 when it tries to write out that buffered data. Thus, you would be
58 left with an incomplete output file and the offending program would
59 exit successfully. Even calling fflush is not always sufficient,
60 since some file systems (NFS and CODA) buffer written/flushed data
61 until an actual close call.
63 Besides, it's wasteful to check the return value from every call
64 that writes to stdout -- just let the internal stream state record
65 the failure. That's what the ferror test is checking below.
67 It's important to detect such failures and exit nonzero because many
68 tools (most notably `make' and other build-management systems) depend
69 on being able to detect failure in other tools via their exit status. */
74 int e = ferror (stdout) ? 0 : -1;
76 if (fclose (stdout) != 0)
81 char const *write_error = _("write error");
83 error (exit_failure, e, "%s: %s", quotearg_colon (file_name),
86 error (exit_failure, e, "%s", write_error);