1cookfp(1) General Commands Manual cookfp(1)
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6 cookfp - calculate file fingerprint
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9 cookfp [ option... ][ filename... ]
10 cookfp -Help
11 cookfp -VERSion
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14 The cookfp program is used to calculate the fingerprints of files. A
15 fingerprint is a hash of the contents of a file. The default finger‐
16 print is cryptographically strong, so the probability of two different
17 files having the same fingerprint is less than 1 in 2**200.
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19 The fingerprint is based on Dan Berstien <djb@silverton.berkeley.edu>
20 public domain fingerprint 0.50 beta package 930809, posted to the
21 alt.sources newsgroup. This program produces identical results; the
22 expected test results were generated using Dan's package.
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24 The fingerprint is a base-64-sanely-encoded fingerprint of the input.
25 Imagine this fingerprint as something universal and permanent. A fin‐
26 gerprint is 76 characters long, containing the following:
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28 1. A Snefru-8 (version 2.5, 8 passes, 512->256) hash. (Derived from
29 the Xerox Secure Hash Function.)
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31 2. An MD5 hash, as per RFC 1321. (Derived from the RSADSI MD5 Mes‐
32 sage-Digest Algorithm.)
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34 3. A CRC checksum, as in the new cksum utility.
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36 4. Length modulo 2^40.
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38 The output format is not expected to be compatible with anything. How‐
39 ever, options are available to produce the purported output of Merkle's
40 snefru program, the purported output of RSADSI's mddriver -x, or the
41 purported output of the POSIX cksum program.
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43 If no files are named as input, the standard input will be used. The
44 special file name ``-'' is understood to mean the standard input.
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47 The following options are understood:
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49 -Checksum
50 Print the CRC32 checksum and length of the named file(s).
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52 -Identifier
53 Print a condensed form of the fingerprint (obtained by perform‐
54 ing a CRC32 checksum on the full fingerprint described above -
55 a definite overkill). This is an 8-digit hexadecimal number,
56 useful for generating unique short identifiers out of long
57 names. The first character is forced to be a letter (g-p), so
58 there is no problem in using the output as a variable name.
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60 -Help
61 Provide some help with using the cookfp program.
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63 -Message_Digest
64 Print the RSA Data Security, Inc. MD5 Message-Digest Algorithm
65 hash of the named file(s).
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67 -Snefru Print the Snefru hash of the named file(s), derived from the
68 Xerox Secure Hash Function.
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70 -VERSion
71 Print the version of the cookfp program being executed.
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73 All other options will produce a diagnostic error.
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75 All options may be abbreviated; the abbreviation is documented as the
76 upper case letters, all lower case letters and underscores (_) are
77 optional. You must use consecutive sequences of optional letters.
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79 All options are case insensitive, you may type them in upper case or
80 lower case or a combination of both, case is not important.
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82 For example: the arguments "-help", "-HEL" and "-h" are all interpreted
83 to mean the -Help option. The argument "-hlp" will not be understood,
84 because consecutive optional characters were not supplied.
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86 Options and other command line arguments may be mixed arbitrarily on
87 the command line.
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89 The GNU long option names are understood. Since all option names for
90 cookfp are long, this means ignoring the extra leading '-'. The
91 "--option=value" convention is also understood.
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94 The cookfp command will exit with a status of 1 on any error. The
95 cookfp command will only exit with a status of 0 if there are no
96 errors.
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99 cookfp version 2.30
100 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
101 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Peter
102 Miller; All rights reserved.
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104 The cookfp program comes with ABSOLUTELY NO WARRANTY; for details use
105 the 'cookfp -VERSion License' command. This is free software and you
106 are welcome to redistribute it under certain conditions; for details
107 use the 'cookfp -VERSion License' command.
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110 Peter Miller E-Mail: millerp@canb.auug.org.au
111 /\/\* WWW: http://www.canb.auug.org.au/~millerp/
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113 Portions of this program are derived from sources from other people,
114 sometimes with liberal copyrights, and sometimes in the public domain.
115 These include:
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117 Dan Bernstien
118 See common/fp/README for details.
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120 Gary S Brown.
121 See common/fp/crc32.c for details.
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123 RSA Data Security, Inc.
124 See common/fp/md5.c for details.
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126 Xerox Corporation
127 See common/fp/snefru.c for details.
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129 In addition to the above copyright holders, there have been numerous
130 authors and contributors, see the named files for details. Files names
131 are relative to the root of the cook distribution.
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135Reference Manual Cook cookfp(1)