initial import of NetBSD tree

1 files changed, 160 insertions, 0 deletions

diff --git a/games/caesar/caesar.c b/games/caesar/caesar.c
new file mode 100644
index 00000000000..de5a2e8a620
--- /dev/null
+++ b/games/caesar/caesar.c
@@ -0,0 +1,160 @@
+/*	$NetBSD: caesar.c,v 1.3 1995/03/21 15:08:21 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Rick Adams.
+ *
+ * Authors:
+ *	Stan King, John Eldridge, based on algorithm suggested by
+ *	Bob Morris
+ * 29-Sep-82
+ *
+ * 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) 1989, 1993\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)caesar.c	8.1 (Berkeley) 5/31/93";
+#else
+static char rcsid[] = "$NetBSD: caesar.c,v 1.3 1995/03/21 15:08:21 cgd Exp $";
+#endif
+#endif /* not lint */
+
+#include <math.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <unistd.h>
+
+#define	LINELENGTH	2048
+#define	ROTATE(ch, perm) \
+	isupper(ch) ? ('A' + (ch - 'A' + perm) % 26) : \
+	    islower(ch) ? ('a' + (ch - 'a' + perm) % 26) : ch
+
+/*
+ * letter frequencies (taken from some unix(tm) documentation)
+ * (unix is a trademark of Bell Laboratories)
+ */
+double stdf[26] = {
+	7.97, 1.35, 3.61, 4.78, 12.37, 2.01, 1.46, 4.49, 6.39, 0.04,
+	0.42, 3.81, 2.69, 5.92,  6.96, 2.91, 0.08, 6.63, 8.77, 9.68,
+	2.62, 0.81, 1.88, 0.23,  2.07, 0.06,
+};
+
+main(argc, argv)
+	int argc;
+	char **argv;
+{
+	extern int errno;
+	register int ch, dot, i, nread, winnerdot;
+	register char *inbuf;
+	int obs[26], try, winner;
+	char *malloc(), *strerror();
+
+	if (argc > 1)
+		printit(argv[1]);
+
+	if (!(inbuf = malloc(LINELENGTH))) {
+		(void)fprintf(stderr, "caesar: out of memory.\n");
+		exit(1);
+	}
+
+	/* adjust frequency table to weight low probs REAL low */
+	for (i = 0; i < 26; ++i)
+		stdf[i] = log(stdf[i]) + log(26.0 / 100.0);
+
+	/* zero out observation table */
+	bzero(obs, 26 * sizeof(int));
+
+	if ((nread = read(STDIN_FILENO, inbuf, LINELENGTH)) < 0) {
+		(void)fprintf(stderr, "caesar: %s\n", strerror(errno));
+		exit(1);
+	}
+	for (i = nread; i--;) {
+		ch = inbuf[i];
+		if (islower(ch))
+			++obs[ch - 'a'];
+		else if (isupper(ch))
+			++obs[ch - 'A'];
+	}
+
+	/*
+	 * now "dot" the freqs with the observed letter freqs
+	 * and keep track of best fit
+	 */
+	for (try = winner = 0; try < 26; ++try) { /* += 13) { */
+		dot = 0;
+		for (i = 0; i < 26; i++)
+			dot += obs[i] * stdf[(i + try) % 26];
+		/* initialize winning score */
+		if (try == 0)
+			winnerdot = dot;
+		if (dot > winnerdot) {
+			/* got a new winner! */
+			winner = try;
+			winnerdot = dot;
+		}
+	}
+
+	for (;;) {
+		for (i = 0; i < nread; ++i) {
+			ch = inbuf[i];
+			putchar(ROTATE(ch, winner));
+		}
+		if (nread < LINELENGTH)
+			break;
+		if ((nread = read(STDIN_FILENO, inbuf, LINELENGTH)) < 0) {
+			(void)fprintf(stderr, "caesar: %s\n", strerror(errno));
+			exit(1);
+		}
+	}
+	exit(0);
+}
+
+printit(arg)
+	char *arg;
+{
+	register int ch, rot;
+
+	if ((rot = atoi(arg)) < 0) {
+		(void)fprintf(stderr, "caesar: bad rotation value.\n");
+		exit(1);
+	}
+	while ((ch = getchar()) != EOF)
+		putchar(ROTATE(ch, rot));
+	exit(0);
+}