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caesar - sync with FreeBSD 2.0

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This commit is contained in:
sinetek
2015-07-03 13:12:25 +07:00
parent 24e057667e
commit 3890f0a6aa
5 changed files with 263 additions and 2 deletions
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4
src/games/Makefile
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@@ -12,8 +12,8 @@ CFLAGS += -Werror -Wall -Os
# Programs that live in subdirectories, and have makefiles of their own.
#
SUBDIR = adventure atc backgammon battlestar boggle btlgammon \
cribbage fortune hangman mille monop quiz robots rogue \
sail snake trek
caesar cribbage fortune hangman mille monop quiz robots \
rogue sail snake trek
# C programs that live in the current directory and do not need
# explicit make lines.

31
src/games/caesar/Makefile Normal file
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@@ -0,0 +1,31 @@
# @(#)Makefile 4.2 (Berkeley) 9/7/85
#
TOPSRC = $(shell cd ../../..; pwd)
include $(TOPSRC)/target.mk
#include $(TOPSRC)/cross.mk
#CFLAGS = -O -DCROSS -Werror -Wall
#CFLAGS += -Werror -Wall
LIBS = -lm -lc
OBJS = caesar.o
MAN = caesar.0
all: caesar $(MAN)
caesar: $(OBJS)
$(CC) $(LDFLAGS) -o $@.elf $(OBJS) $(LIBS)
$(OBJDUMP) -S $@.elf > $@.dis
$(SIZE) $@.elf
$(ELF2AOUT) $@.elf $@ && rm $@.elf
$(MAN): caesar.6
nroff -man $< > $@
clean:
rm -f *.o core caesar *.0 *.dis
install: all
install caesar $(DESTDIR)/games/
install -m 644 $(MAN) $(DESTDIR)/share/man/cat6/

74
src/games/caesar/caesar.6 Normal file
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@@ -0,0 +1,74 @@
.\" Copyright (c) 1989, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" 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.
.\"
.\" @(#)caesar.6 8.2 (Berkeley) 11/16/93
.\"
.Dd November 16, 1993
.Dt CAESAR 6
.Os
.Sh NAME
.Nm caesar
.Nd decrypt caesar cyphers
.Sh SYNOPSIS
.Nm caesar
.Op Ar rotation
.Sh DESCRIPTION
The
.Nm caesar
utility attempts to decrypt caesar cyphers using English letter frequency
statistics.
.Nm Caesar
reads from the standard input and writes to the standard output.
.Pp
The optional numerical argument
Ar rotation
may be used to specify a specific rotation value.
.Pp
The frequency (from most common to least) of English letters is as follows:
.Pp
.Bd -filled -offset indent
ETAONRISHDLFCMUGPYWBVKXJQZ
.Ed
.Pp
Their frequencies as a percentage are as follows:
.Pp
.Bd -filled -offset indent
E(13), T(10.5), A(8.1), O(7.9), N(7.1), R(6.8), I(6.3), S(6.1), H(5.2),
D(3.8), L(3.4), F(2.9), C(2.7), M(2.5), U(2.4), G(2),
P(1.9), Y(1.9),
W(1.5), B(1.4), V(.9), K(.4), X(.15), J(.13), Q(.11), Z(.07).
.Ed
.Pp
Rotated postings to
.Tn USENET
and some of the databases used by the
.Xr fortune 6
program are rotated by 13 characters.

154
src/games/caesar/caesar.c Normal file
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/*
* 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
static char sccsid[] = "@(#)caesar.c 8.1 (Berkeley) 5/31/93";
#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);
}