xref: /freebsd/usr.bin/caesar/caesar.6 (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
1*6ae1554aSColin Percival.\" Copyright (c) 1989, 1991, 1993
2*6ae1554aSColin Percival.\"	The Regents of the University of California.  All rights reserved.
3*6ae1554aSColin Percival.\"
4*6ae1554aSColin Percival.\" Redistribution and use in source and binary forms, with or without
5*6ae1554aSColin Percival.\" modification, are permitted provided that the following conditions
6*6ae1554aSColin Percival.\" are met:
7*6ae1554aSColin Percival.\" 1. Redistributions of source code must retain the above copyright
8*6ae1554aSColin Percival.\"    notice, this list of conditions and the following disclaimer.
9*6ae1554aSColin Percival.\" 2. Redistributions in binary form must reproduce the above copyright
10*6ae1554aSColin Percival.\"    notice, this list of conditions and the following disclaimer in the
11*6ae1554aSColin Percival.\"    documentation and/or other materials provided with the distribution.
12*6ae1554aSColin Percival.\" 3. Neither the name of the University nor the names of its contributors
13*6ae1554aSColin Percival.\"    may be used to endorse or promote products derived from this software
14*6ae1554aSColin Percival.\"    without specific prior written permission.
15*6ae1554aSColin Percival.\"
16*6ae1554aSColin Percival.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17*6ae1554aSColin Percival.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18*6ae1554aSColin Percival.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19*6ae1554aSColin Percival.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20*6ae1554aSColin Percival.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21*6ae1554aSColin Percival.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22*6ae1554aSColin Percival.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23*6ae1554aSColin Percival.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24*6ae1554aSColin Percival.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25*6ae1554aSColin Percival.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26*6ae1554aSColin Percival.\" SUCH DAMAGE.
27*6ae1554aSColin Percival.\"
28*6ae1554aSColin Percival.Dd November 16, 1993
29*6ae1554aSColin Percival.Dt CAESAR 6
30*6ae1554aSColin Percival.Os
31*6ae1554aSColin Percival.Sh NAME
32*6ae1554aSColin Percival.Nm caesar , rot13
33*6ae1554aSColin Percival.Nd decrypt caesar ciphers
34*6ae1554aSColin Percival.Sh SYNOPSIS
35*6ae1554aSColin Percival.Nm
36*6ae1554aSColin Percival.Op Ar rotation
37*6ae1554aSColin Percival.Nm rot13
38*6ae1554aSColin Percival.Sh DESCRIPTION
39*6ae1554aSColin PercivalThe
40*6ae1554aSColin Percival.Nm
41*6ae1554aSColin Percivalutility attempts to decrypt caesar ciphers using English letter frequency
42*6ae1554aSColin Percivalstatistics.
43*6ae1554aSColin Percival.Nm Caesar
44*6ae1554aSColin Percivalreads from the standard input and writes to the standard output.
45*6ae1554aSColin Percival.Pp
46*6ae1554aSColin PercivalThe optional numerical argument
47*6ae1554aSColin Percival.Ar rotation
48*6ae1554aSColin Percivalmay be used to specify a specific rotation value.
49*6ae1554aSColin PercivalIf invoked as
50*6ae1554aSColin Percival.Nm rot13 ,
51*6ae1554aSColin Percivala rotation value of 13 will be used.
52*6ae1554aSColin Percival.Pp
53*6ae1554aSColin PercivalThe frequency (from most common to least) of English letters is as follows:
54*6ae1554aSColin Percival.Bd -ragged -offset indent
55*6ae1554aSColin PercivalETAONRISHDLFCMUGPYWBVKXJQZ
56*6ae1554aSColin Percival.Ed
57*6ae1554aSColin Percival.Pp
58*6ae1554aSColin PercivalTheir frequencies as a percentage are as follows:
59*6ae1554aSColin Percival.Bd -ragged -offset indent
60*6ae1554aSColin PercivalE(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),
61*6ae1554aSColin PercivalD(3.8), L(3.4), F(2.9), C(2.7), M(2.5), U(2.4), G(2),
62*6ae1554aSColin PercivalP(1.9), Y(1.9),
63*6ae1554aSColin PercivalW(1.5), B(1.4), V(.9), K(.4), X(.15), J(.13), Q(.11), Z(.07).
64*6ae1554aSColin Percival.Ed
65*6ae1554aSColin Percival.Pp
66*6ae1554aSColin PercivalRotated postings to
67*6ae1554aSColin Percival.Tn USENET
68*6ae1554aSColin Percivaland some of the databases used by the
69*6ae1554aSColin Percival.Xr fortune 6
70*6ae1554aSColin Percivalprogram are rotated by 13 characters.
71