/* $NetBSD: xexit.c,v 1.1.1.1 2016/01/14 00:11:29 christos Exp $ */ /* xexit.c -- exit with attention to return values and closing stdout. Id: xexit.c,v 1.5 2004/04/11 17:56:46 karl Exp Copyright (C) 1999, 2003, 2004 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "system.h" /* SunOS 4.1.1 gets STDC_HEADERS defined, but it doesn't provide EXIT_FAILURE. So far no system has defined one of EXIT_FAILURE and EXIT_SUCCESS without the other. */ #ifdef EXIT_SUCCESS /* The following test is to work around the gross typo in systems like Sony NEWS-OS Release 4.0C, whereby EXIT_FAILURE is defined to 0, not 1. */ # if !EXIT_FAILURE # undef EXIT_FAILURE # define EXIT_FAILURE 1 # endif #else /* not EXIT_SUCCESS */ # ifdef VMS /* these values suppress some messages; from gnuplot */ # define EXIT_SUCCESS 1 # define EXIT_FAILURE 0x10000002 # else /* not VMS */ # define EXIT_SUCCESS 0 # define EXIT_FAILURE 1 # endif /* not VMS */ #endif /* not EXIT_SUCCESS */ /* Flush stdout first, exit if failure (therefore, xexit should be called to exit every program, not just `return' from main). Otherwise, if EXIT_STATUS is zero, exit successfully, else unsuccessfully. */ void xexit (int exit_status) { if (ferror (stdout)) { fputs (_("ferror on stdout\n"), stderr); exit_status = 1; } else if (fflush (stdout) != 0) { fputs (_("fflush error on stdout\n"), stderr); exit_status = 1; } exit_status = exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE; exit (exit_status); } /* Why do we care about stdout you may ask? Here's why, from Jim Meyering in the lib/closeout.c file. */ /* If a program writes *anything* to stdout, that program should close stdout and make sure that the close succeeds. Otherwise, suppose that you go to the extreme of checking the return status of every function that does an explicit write to stdout. The last printf can succeed in writing to the internal stream buffer, and yet the fclose(stdout) could still fail (due e.g., to a disk full error) when it tries to write out that buffered data. Thus, you would be left with an incomplete output file and the offending program would exit successfully. Besides, it's wasteful to check the return value from every call that writes to stdout -- just let the internal stream state record the failure. That's what the ferror test is checking below. It's important to detect such failures and exit nonzero because many tools (most notably `make' and other build-management systems) depend on being able to detect failure in other tools via their exit status. */