1 /* $NetBSD: xexit.c,v 1.1.1.1 2016/01/14 00:11:29 christos Exp $ */
2
3 /* xexit.c -- exit with attention to return values and closing stdout.
4 Id: xexit.c,v 1.5 2004/04/11 17:56:46 karl Exp
5
6 Copyright (C) 1999, 2003, 2004 Free Software Foundation, Inc.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21
22 #include "system.h"
23
24 /* SunOS 4.1.1 gets STDC_HEADERS defined, but it doesn't provide
25 EXIT_FAILURE. So far no system has defined one of EXIT_FAILURE and
26 EXIT_SUCCESS without the other. */
27 #ifdef EXIT_SUCCESS
28 /* The following test is to work around the gross typo in
29 systems like Sony NEWS-OS Release 4.0C, whereby EXIT_FAILURE
30 is defined to 0, not 1. */
31 # if !EXIT_FAILURE
32 # undef EXIT_FAILURE
33 # define EXIT_FAILURE 1
34 # endif
35 #else /* not EXIT_SUCCESS */
36 # ifdef VMS /* these values suppress some messages; from gnuplot */
37 # define EXIT_SUCCESS 1
38 # define EXIT_FAILURE 0x10000002
39 # else /* not VMS */
40 # define EXIT_SUCCESS 0
41 # define EXIT_FAILURE 1
42 # endif /* not VMS */
43 #endif /* not EXIT_SUCCESS */
44
45
46 /* Flush stdout first, exit if failure (therefore, xexit should be
47 called to exit every program, not just `return' from main).
48 Otherwise, if EXIT_STATUS is zero, exit successfully, else
49 unsuccessfully. */
50
51 void
xexit(int exit_status)52 xexit (int exit_status)
53 {
54 if (ferror (stdout))
55 {
56 fputs (_("ferror on stdout\n"), stderr);
57 exit_status = 1;
58 }
59 else if (fflush (stdout) != 0)
60 {
61 fputs (_("fflush error on stdout\n"), stderr);
62 exit_status = 1;
63 }
64
65 exit_status = exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
66
67 exit (exit_status);
68 }
69
70
71 /* Why do we care about stdout you may ask? Here's why, from Jim
72 Meyering in the lib/closeout.c file. */
73
74 /* If a program writes *anything* to stdout, that program should close
75 stdout and make sure that the close succeeds. Otherwise, suppose that
76 you go to the extreme of checking the return status of every function
77 that does an explicit write to stdout. The last printf can succeed in
78 writing to the internal stream buffer, and yet the fclose(stdout) could
79 still fail (due e.g., to a disk full error) when it tries to write
80 out that buffered data. Thus, you would be left with an incomplete
81 output file and the offending program would exit successfully.
82
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.
86
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. */
90