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[coreutils.git] / lib / closeout.c
blobbdda59feeb019a1aa38237802acaecb3d8248e2b
1 /* closeout.c - close standard output
2 Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
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.
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.
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. */
18 #if HAVE_CONFIG_H
19 # include <config.h>
20 #endif
22 #if ENABLE_NLS
23 # include <libintl.h>
24 # define _(Text) gettext (Text)
25 #else
26 # define _(Text) Text
27 #endif
29 #if HAVE_STDLIB_H
30 # include <stdlib.h>
31 #endif
32 #ifndef EXIT_FAILURE
33 # define EXIT_FAILURE 1
34 #endif
36 #include <stdio.h>
38 #include <errno.h>
39 #ifndef errno
40 extern int errno;
41 #endif
43 #include "closeout.h"
44 #include "error.h"
45 #include "quotearg.h"
46 #include "__fpending.h"
48 static int default_exit_status = EXIT_FAILURE;
49 static const char *file_name;
51 /* Set the value to be used for the exit status when close_stdout is called.
52 This is useful when it is not convenient to call close_stdout_status,
53 e.g., when close_stdout is called via atexit. */
54 void
55 close_stdout_set_status (int status)
57 default_exit_status = status;
60 /* Set the file name to be reported in the event an error is detected
61 by close_stdout_status. */
62 void
63 close_stdout_set_file_name (const char *file)
65 file_name = file;
68 /* Close standard output, exiting with status STATUS on failure.
69 If a program writes *anything* to stdout, that program should `fflush'
70 stdout and make sure that it succeeds before exiting. Otherwise,
71 suppose that you go to the extreme of checking the return status
72 of every function that does an explicit write to stdout. The last
73 printf can succeed in writing to the internal stream buffer, and yet
74 the fclose(stdout) could still fail (due e.g., to a disk full error)
75 when it tries to write out that buffered data. Thus, you would be
76 left with an incomplete output file and the offending program would
77 exit successfully.
79 FIXME: note the fflush suggested above is implicit in the fclose
80 we actually do below. Consider doing only the fflush and/or using
81 setvbuf to inhibit buffering.
83 Besides, it's wasteful to check the return value from every call
84 that writes to stdout -- just let the internal stream state record
85 the failure. That's what the ferror test is checking below.
87 It's important to detect such failures and exit nonzero because many
88 tools (most notably `make' and other build-management systems) depend
89 on being able to detect failure in other tools via their exit status. */
91 void
92 close_stdout_status (int status)
94 int e = ferror (stdout) ? 0 : -1;
96 if (__fpending (stdout) == 0)
97 return;
99 if (fclose (stdout) != 0)
100 e = errno;
102 if (0 <= e)
104 char const *write_error = _("write error");
105 if (file_name)
106 error (status, e, "%s: %s", quotearg_colon (file_name), write_error);
107 else
108 error (status, e, "%s", write_error);
112 /* Close standard output, exiting with status EXIT_FAILURE on failure. */
113 void
114 close_stdout (void)
116 close_stdout_status (default_exit_status);