rot13(6) [netbsd man page]
CAESAR(6) BSD Games Manual CAESAR(6) NAME
caesar, rot13 -- decrypt caesar ciphers SYNOPSIS
caesar [rotation] DESCRIPTION
The caesar utility attempts to decrypt caesar ciphers using English letter frequency statistics. caesar reads from the standard input and writes to the standard output. The optional numerical argument rotation may be used to specify a specific rotation value. The frequency (from most common to least) of English letters is as follows: ETAONRISHDLFCMUGPYWBVKXJQZ Their frequencies as a percentage are as follows: 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). Rotated postings to USENET and some of the databases used by the fortune(6) program are rotated by 13 characters. BSD
November 16, 1993 BSD
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STRFILE(8) BSD System Manager's Manual STRFILE(8) NAME
strfile, unstr -- create a random access file for storing strings SYNOPSIS
strfile [-Ciorsx] [-c char] source_file [output_file] unstr source_file DESCRIPTION
The strfile utility reads a file containing groups of lines separated by a line containing a single percent '%' sign and creates a data file which contains a header structure and a table of file offsets for each group of lines. This allows random access of the strings. The output file, if not specified on the command line, is named source_file.dat. The options are as follows: -C Flag the file as containing comments. This option cases the STR_COMMENTS bit in the header str_flags field to be set. Comments are designated by two delimiter characters at the beginning of the line, though strfile does not give any special treatment to comment lines. -c char Change the delimiting character from the percent sign to char. -i Ignore case when ordering the strings. -o Order the strings in alphabetical order. The offset table will be sorted in the alphabetical order of the groups of lines refer- enced. Any initial non-alphanumeric characters are ignored. This option causes the STR_ORDERED bit in the header str_flags field to be set. -r Randomize access to the strings. Entries in the offset table will be randomly ordered. This option causes the STR_RANDOM bit in the header str_flags field to be set. -s Run silently; do not give a summary message when finished. -x Note that each alphabetic character in the groups of lines is rotated 13 positions in a simple caesar cypher. This option causes the STR_ROTATED bit in the header str_flags field to be set. The format of the header is: #define VERSION 1 uint32_t str_version; /* version number */ uint32_t str_numstr; /* # of strings in the file */ uint32_t str_longlen; /* length of longest string */ uint32_t str_shortlen; /* length of shortest string */ #define STR_RANDOM 0x1 /* randomized pointers */ #define STR_ORDERED 0x2 /* ordered pointers */ #define STR_ROTATED 0x4 /* rot-13'd text */ #define STR_COMMENTS 0x8 /* embedded comments */ uint32_t str_flags; /* bit field for flags */ char str_delim; /* delimiting character */ All fields are written in network byte order. The purpose of unstr is to undo the work of strfile. It prints out the strings contained in the file source_file in the order that they are listed in the header file source_file.dat to standard output. It is possible to create sorted versions of input files by using -o when strfile is run and then using unstr to dump them out in the table order. FILES
strfile.dat default output file. SEE ALSO
byteorder(3), fortune(6) HISTORY
The strfile utility first appeared in 4.4BSD. BSD
February 17, 2005 BSD