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authorTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
committerTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
commitd6583bb2a13f329cf0332ef2570eb8bb8fc0e39c (patch)
treeece253b876159b39c620e62b6c9b1174642e070e /games/random/random.c
initial import of NetBSD tree
Diffstat (limited to 'games/random/random.c')
-rw-r--r--games/random/random.c155
1 files changed, 155 insertions, 0 deletions
diff --git a/games/random/random.c b/games/random/random.c
new file mode 100644
index 00000000000..96267e253e1
--- /dev/null
+++ b/games/random/random.c
@@ -0,0 +1,155 @@
+/* $NetBSD: random.c,v 1.3 1995/04/22 07:44:05 cgd Exp $ */
+
+/*
+ * Copyright (c) 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Guy Harris at Network Appliance Corp.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char copyright[] =
+"@(#) Copyright (c) 1994\n\
+ The Regents of the University of California. All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)random.c 8.5 (Berkeley) 4/5/94";
+#else
+static char rcsid[] = "$NetBSD: random.c,v 1.3 1995/04/22 07:44:05 cgd Exp $";
+#endif
+#endif /* not lint */
+
+#include <sys/types.h>
+
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <limits.h>
+
+void usage __P((void));
+
+int
+main(argc, argv)
+ int argc;
+ char *argv[];
+{
+ extern int optind;
+ time_t now;
+ double denom;
+ int ch, random_exit, selected, unbuffer_output;
+ char *ep;
+
+ random_exit = unbuffer_output = 0;
+ while ((ch = getopt(argc, argv, "er")) != EOF)
+ switch (ch) {
+ case 'e':
+ random_exit = 1;
+ break;
+ case 'r':
+ unbuffer_output = 1;
+ break;
+ default:
+ case '?':
+ usage();
+ /* NOTREACHED */
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ switch (argc) {
+ case 0:
+ denom = 2;
+ break;
+ case 1:
+ errno = 0;
+ denom = strtod(*argv, &ep);
+ if (errno == ERANGE)
+ err(1, "%s", *argv);
+ if (denom == 0 || *ep != '\0')
+ errx(1, "denominator is not valid.");
+ break;
+ default:
+ usage();
+ /* NOTREACHED */
+ }
+
+ (void)time(&now);
+ srandom((u_int)(now + getpid()));
+
+ /* Compute a random exit status between 0 and denom - 1. */
+ if (random_exit)
+ return ((denom * random()) / LONG_MAX);
+
+ /*
+ * Act as a filter, randomly choosing lines of the standard input
+ * to write to the standard output.
+ */
+ if (unbuffer_output)
+ setbuf(stdout, NULL);
+
+ /*
+ * Select whether to print the first line. (Prime the pump.)
+ * We find a random number between 0 and denom - 1 and, if it's
+ * 0 (which has a 1 / denom chance of being true), we select the
+ * line.
+ */
+ selected = (int)(denom * random() / LONG_MAX) == 0;
+ while ((ch = getchar()) != EOF) {
+ if (selected)
+ (void)putchar(ch);
+ if (ch == '\n') {
+ /* End of that line. See if we got an error. */
+ if (ferror(stdout))
+ err(2, "stdout");
+
+ /* Now see if the next line is to be printed. */
+ selected = (int)(denom * random() / LONG_MAX) == 0;
+ }
+ }
+ if (ferror(stdin))
+ err(2, "stdin");
+ exit (0);
+}
+
+void
+usage()
+{
+
+ (void)fprintf(stderr, "usage: random [-er] [denominator]\n");
+ exit(1);
+}