72 lines
2.8 KiB
Groff
72 lines
2.8 KiB
Groff
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.\" Copyright (c) 1989 The Regents of the University of California.
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)caesar.6 5.3 (Berkeley) 11/11/90
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.\"
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.TH CAESAR 6 "November 11, 1990"
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.UC 7
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.SH NAME
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caesar \- decrypt caesar cyphers
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.SH SYNOPSIS
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.B caesar
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[
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.B rotation
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]
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.SH DESCRIPTION
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The
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.I caesar
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utility attempts to decrypt caesar cyphers using English letter frequency
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statistics.
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.I Caesar
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reads from the standard input and writes to the standard output.
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.PP
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The optional numerical argument
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.I rotation
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may be used to specify a specific rotation value.
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.PP
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The frequency (from most common to least) of English letters is as follows:
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.sp
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.RS
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ETAONRISHDLFCMUGPYWBVKXJQZ
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.RE
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.PP
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Their frequencies as a percentage are as follows:
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.sp
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.RS
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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),
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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),
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W(1.5), B(1.4), V(.9), K(.4), X(.15), J(.13), Q(.11), Z(.07).
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.RE
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.PP
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Rotated postings to USENET and some of the databases used by the
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.IR fortune (6)
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program are rotated by 13 characters.
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