b03d4fa882
the games. This merges in all such remaining changes from the Linux port of the NetBSD games, except in hunt (where substantial changes from OpenBSD need to be looked at). Most noreturn attributes were previously added in bin/6144, with some others that were missed then in bin/8082. Previous `unused' attributes were covered in bin/6557, bin/8058 and other PRs (all these PRs have already been handled and closed).
158 lines
4.3 KiB
C
158 lines
4.3 KiB
C
/* $NetBSD: random.c,v 1.6 1999/09/08 21:45:29 jsm Exp $ */
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/*
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* Copyright (c) 1994
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Guy Harris at Network Appliance Corp.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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__COPYRIGHT("@(#) Copyright (c) 1994\n\
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The Regents of the University of California. All rights reserved.\n");
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#endif /* not lint */
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)random.c 8.6 (Berkeley) 6/1/94";
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#else
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__RCSID("$NetBSD: random.c,v 1.6 1999/09/08 21:45:29 jsm Exp $");
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#endif
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#endif /* not lint */
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#include <sys/types.h>
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#include <sys/time.h>
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#include <err.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <unistd.h>
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#include <limits.h>
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int main __P((int, char **));
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void usage __P((void)) __attribute__((__noreturn__));
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int
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main(argc, argv)
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int argc;
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char *argv[];
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{
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struct timeval tp;
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double denom;
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int ch, random_exit, selected, unbuffer_output;
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char *ep;
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denom = 0;
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random_exit = unbuffer_output = 0;
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while ((ch = getopt(argc, argv, "er")) != -1)
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switch (ch) {
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case 'e':
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random_exit = 1;
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break;
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case 'r':
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unbuffer_output = 1;
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break;
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default:
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case '?':
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usage();
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/* NOTREACHED */
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}
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argc -= optind;
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argv += optind;
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switch (argc) {
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case 0:
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denom = 2;
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break;
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case 1:
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errno = 0;
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denom = strtod(*argv, &ep);
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if (errno == ERANGE)
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err(1, "%s", *argv);
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if (denom == 0 || *ep != '\0')
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errx(1, "denominator is not valid.");
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break;
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default:
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usage();
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/* NOTREACHED */
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}
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(void)gettimeofday(&tp, NULL);
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srandom((u_int)(tp.tv_usec + tp.tv_sec + getpid()));
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/* Compute a random exit status between 0 and denom - 1. */
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if (random_exit)
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return ((denom * random()) / LONG_MAX);
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/*
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* Act as a filter, randomly choosing lines of the standard input
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* to write to the standard output.
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*/
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if (unbuffer_output)
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setbuf(stdout, NULL);
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/*
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* Select whether to print the first line. (Prime the pump.)
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* We find a random number between 0 and denom - 1 and, if it's
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* 0 (which has a 1 / denom chance of being true), we select the
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* line.
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*/
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selected = (int)(denom * random() / LONG_MAX) == 0;
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while ((ch = getchar()) != EOF) {
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if (selected)
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(void)putchar(ch);
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if (ch == '\n') {
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/* End of that line. See if we got an error. */
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if (ferror(stdout))
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err(2, "stdout");
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/* Now see if the next line is to be printed. */
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selected = (int)(denom * random() / LONG_MAX) == 0;
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}
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}
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if (ferror(stdin))
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err(2, "stdin");
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exit (0);
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}
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void
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usage()
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{
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(void)fprintf(stderr, "usage: random [-er] [denominator]\n");
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exit(1);
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}
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