BSD 4_4 release

[unix-history] / usr / src / games / caesar / caesar.6

diff --git a/usr/src/games/caesar/caesar.6 b/usr/src/games/caesar/caesar.6
index 916f950..5cd5965 100644 (file)
--- a/usr/src/games/caesar/caesar.6
+++ b/usr/src/games/caesar/caesar.6
@@ -1,45 +1,74 @@
-.\" Copyright (c) 1989 The Regents of the University of California.
-.\" All rights reserved.
+.\" Copyright (c) 1989, 1991, 1993
+.\"    The Regents of the University of California.  All rights reserved.

 .\"
 .\"

-.\" Redistribution and use in source and binary forms are permitted provided
-.\" that: (1) source distributions retain this entire copyright notice and
-.\" comment, and (2) distributions including binaries display the following
-.\" acknowledgement:  ``This product includes software developed by the
-.\" University of California, Berkeley and its contributors'' in the
-.\" documentation or other materials provided with the distribution and in
-.\" all advertising materials mentioning features or use of this software.
-.\" 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
-.\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
-.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+.\" 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.

 .\"
 .\"

-.\"    @(#)caesar.6    1.2 (Berkeley) 6/23/90
+.\" 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.

 .\"
 .\"

-.TH CAESAR 6 "June 23, 1990"
-.UC 7
-.SH NAME
-caesar \- decrypt caesar cyphers
-.SH SYNOPSIS
-.B caesar
-[
-.B rotation
-]
-.SH DESCRIPTION
+.\"    @(#)caesar.6    8.1 (Berkeley) 5/31/93
+.\"
+.Dd May 31, 1993
+.Dt CAESAR 6
+.Os
+.Sh NAME
+.Nm caesar
+.Nd decrypt caesar cyphers
+.Sh SYNOPSIS
+.Nm caesar
+.Op Ar rotation
+.Sh DESCRIPTION

 The
 The

-.I caesar
-utility attempts to decrypt caesar cyphers using letter frequency
+Nm caesar
+utility attempts to decrypt caesar cyphers using English letter frequency

 statistics.
 statistics.

-.I Caesar
+Nm Caesar

 reads from the standard input and writes to the standard output.
 reads from the standard input and writes to the standard output.

-.PP
+.Pp

 The optional numerical argument
 The optional numerical argument

-.I rotation
+Ar rotation

 may be used to specify a specific rotation value.
 may be used to specify a specific rotation value.

-For example,
-.B "caesar 13"
-may be used to decrypt rotated postings to USENET
-as well as some of the databases used with the
-.I fortune
-program.
+.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.