87 lines
3.1 KiB
C
87 lines
3.1 KiB
C
/* xexit.c -- exit with attention to return values and closing stdout.
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$Id: xexit.c,v 1.5 1999/02/19 14:13:51 karl Exp $
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Copyright (C) 1999 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "system.h"
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/* SunOS 4.1.1 gets STDC_HEADERS defined, but it doesn't provide
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EXIT_FAILURE. So far no system has defined one of EXIT_FAILURE and
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EXIT_SUCCESS without the other. */
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#ifdef EXIT_SUCCESS
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/* The following test is to work around the gross typo in
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systems like Sony NEWS-OS Release 4.0C, whereby EXIT_FAILURE
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is defined to 0, not 1. */
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# if !EXIT_FAILURE
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# undef EXIT_FAILURE
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# define EXIT_FAILURE 1
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# endif
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#else /* not EXIT_SUCCESS */
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# ifdef VMS /* these values suppress some messages; from gnuplot */
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# define EXIT_SUCCESS 1
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# define EXIT_FAILURE 0x10000002
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# else /* not VMS */
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# define EXIT_SUCCESS 0
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# define EXIT_FAILURE 1
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# endif /* not VMS */
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#endif /* not EXIT_SUCCESS */
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/* Flush stdout first, exit if failure. Otherwise, if EXIT_STATUS is
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zero, exit successfully, else unsuccessfully. */
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void
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xexit (exit_status)
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int exit_status;
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{
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if (ferror (stdout))
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{
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fprintf (stderr, "ferror on stdout");
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exit_status = 1;
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}
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else if (fflush (stdout) != 0)
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{
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fprintf (stderr, "fflush error on stdout");
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exit_status = 1;
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}
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exit_status = exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
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exit (exit_status);
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}
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/* Why do we care about stdout you may ask? Here's why, from Jim
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Meyering in the lib/closeout.c file. */
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/* If a program writes *anything* to stdout, that program should close
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stdout and make sure that the close succeeds. Otherwise, suppose that
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you go to the extreme of checking the return status of every function
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that does an explicit write to stdout. The last printf can succeed in
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writing to the internal stream buffer, and yet the fclose(stdout) could
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still fail (due e.g., to a disk full error) when it tries to write
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out that buffered data. Thus, you would be left with an incomplete
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output file and the offending program would exit successfully.
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Besides, it's wasteful to check the return value from every call
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that writes to stdout -- just let the internal stream state record
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the failure. That's what the ferror test is checking below.
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It's important to detect such failures and exit nonzero because many
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tools (most notably `make' and other build-management systems) depend
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on being able to detect failure in other tools via their exit status. */
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