/* * have_posscl - determine if we have a scalar FILEPOS element * * Copyright (C) 1999,2021 Landon Curt Noll * * Calc is open software; you can redistribute it and/or modify it under * the terms of the version 2.1 of the GNU Lesser General Public License * as published by the Free Software Foundation. * * Calc 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 Lesser General * Public License for more details. * * A copy of version 2.1 of the GNU Lesser General Public License is * distributed with calc under the filename COPYING-LGPL. You should have * received a copy with calc; if not, write to Free Software Foundation, Inc. * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * Under source code control: 1996/07/13 12:57:22 * File existed as early as: 1996 * * chongo /\oo/\ http://www.isthe.com/chongo/ * Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/ */ /* * usage: * have_posscl * * On some systems, FILEPOS is a scalar value on which one can perform * arithmetic operations, assignments and comparisons. On some systems * FILEPOS is some sort of union or struct which must be converted into * a ZVALUE in order to perform arithmetic operations, assignments and * comparisons. * * This prog outputs several defines: * * HAVE_FILEPOS_SCALAR * defined ==> ok to perform arithmetic ops, = and comparisons * undefined ==> convert to ZVALUE first */ #include #include #include #include "have_unistd.h" #if defined(HAVE_UNISTD_H) #include #endif #include "have_fpos.h" int main(void) { #if !defined(FILEPOS_NON_SCALAR) FILEPOS value; /* an FILEPOS to perform arithmatic on */ FILEPOS value2; /* an FILEPOS to perform arithmatic on */ /* * do some math opts on an FILEPOS */ value = (FILEPOS)getpid(); value2 = (FILEPOS)-1; if (value > (FILEPOS)1) { --value; } #if !defined(_WIN32) if (value <= (FILEPOS)getppid()) { --value; } #endif if (value == value2) { value += value2; } value <<= 1; if (!value) { printf("/* something for the FILEPOS to do */\n"); } /* * report FILEPOS as a scalar */ printf("#undef HAVE_FILEPOS_SCALAR\n"); printf("#define HAVE_FILEPOS_SCALAR /* FILEPOS is a simple value */\n"); #else printf("#undef HAVE_FILEPOS_SCALAR " "/* FILEPOS is not a simple value */\n"); #endif /* exit(0); */ return 0; }