diff options
Diffstat (limited to 'usr.bin/caesar/caesar.6')
| -rw-r--r-- | usr.bin/caesar/caesar.6 | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/usr.bin/caesar/caesar.6 b/usr.bin/caesar/caesar.6 new file mode 100644 index 000000000000..403370d57e36 --- /dev/null +++ b/usr.bin/caesar/caesar.6 @@ -0,0 +1,70 @@ +.\" 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. 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. +.\" +.Dd November 16, 1993 +.Dt CAESAR 6 +.Os +.Sh NAME +.Nm caesar , rot13 +.Nd decrypt caesar ciphers +.Sh SYNOPSIS +.Nm +.Op Ar rotation +.Nm rot13 +.Sh DESCRIPTION +The +.Nm +utility attempts to decrypt caesar ciphers 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. +If invoked as +.Nm rot13 , +a rotation value of 13 will be used. +.Pp +The frequency (from most common to least) of English letters is as follows: +.Bd -ragged -offset indent +ETAONRISHDLFCMUGPYWBVKXJQZ +.Ed +.Pp +Their frequencies as a percentage are as follows: +.Bd -ragged -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. |