xenial (1) aefp.1.gz

Provided by: aegis_4.24.3-3_amd64 bug

NAME

       aefp - calculate file fingerprint

SYNOPSIS

       aefp [ option...  ][ filename...  ]
       aefp -Help
       aefp -VERSion

DESCRIPTION

       The aefp program is used to calculate the fingerprints of files.  A fingerprint is a hash of the contents
       of a file.  The default fingerprint is cryptographically strong, so  the  probability  of  two  different
       files having the same fingerprint is less than 1 in 2**200.

       The fingerprint is based on Dan Berstien <djb@silverton.berkeley.edu> public domain fingerprint 0.50 beta
       package 930809, posted to the alt.sources  newsgroup.   This  program  produces  identical  results;  the
       expected test results were generated using Dan's package.

       The  fingerprint  is  a  base-64-sanely-encoded  fingerprint  of  the input.  Imagine this fingerprint as
       something universal and permanent.  A fingerprint is 76 characters long, containing the following:

       1.  A Snefru-8 (version 2.5, 8 passes, 512->256) hash.  (Derived from the Xerox Secure Hash Function.)

       2.  An MD5 hash, as per RFC 1321.  (Derived from the RSADSI MD5 Message-Digest Algorithm.)

       3.  A CRC checksum, as in the new cksum utility.

       4.  Length modulo 2^40.

       The output format is not expected to be compatible with anything.   However,  options  are  available  to
       produce the purported output of Merkle's snefru program, the purported output of RSADSI's mddriver -x, or
       the purported output of the POSIX cksum program.

       If no files are named as input, the standard input will be used.  The special file name “-” is understood
       to mean the standard input.

OPTIONS

       The following options are understood:

       -Checksum
               Print the CRC32 checksum and length of the named file(s).

       -Identifier
               Print  a  condensed  form of the fingerprint (obtained by performing a CRC32 checksum on the full
               fingerprint described above - a definite overkill).   This  is  an  8-digit  hexadecimal  number,
               useful  for generating unique short identifiers out of long names.  The first character is forced
               to be a letter (g-p), so there is no problem in using the output as a variable name.

       -Help
               Provide some help with using the aefp program.

       -Message_Digest
               Print the RSA Data Security, Inc. MD5 Message-Digest Algorithm hash of the named file(s).

       -Snefru Print the Snefru hash of the named file(s), derived from the Xerox Secure Hash Function.

       -VERSion
               Print the version of the aefp program being executed.

       All other options will produce a diagnostic error.

       All options may be abbreviated; the abbreviation is documented as the upper case letters, all lower  case
       letters and underscores (_) are optional.  You must use consecutive sequences of optional letters.

       All options are case insensitive, you may type them in upper case or lower case or a combination of both,
       case is not important.

       For example: the arguments "-project, "-PROJ" and "-p" are all interpreted to mean the  -Project  option.
       The argument "-prj" will not be understood, because consecutive optional characters were not supplied.

       Options and other command line arguments may be mixed arbitrarily on the command line, after the function
       selectors.

       The GNU long option names are understood.  Since all option names for aefp are long, this means  ignoring
       the extra leading '-'.  The "--option=value" convention is also understood.

EXIT STATUS

       The  aefp  command  will  exit  with  a status of 1 on any error.  The aefp command will only exit with a
       status of 0 if there are no errors.

ENVIRONMENT VARIABLES

       See aegis(1) for a list of environment variables which may affect this command.  See aepconf(5)  for  the
       project configuration file's project_specific field for how to set environment variables for all commands
       executed by Aegis.

       aefp version 4.24.3.D001
       Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,  2004,  2005,
       2006, 2007, 2008, 2009, 2010 Peter Miller

       The  aefp program comes with ABSOLUTELY NO WARRANTY; for details use the 'aefp -VERSion License' command.
       This is free software and you are welcome to redistribute it under certain conditions;  for  details  use
       the 'aefp -VERSion License' command.

AUTHOR

       Peter Miller   E-Mail:   millerp@canb.auug.org.au
       /\/\*             WWW:   http://www.canb.auug.org.au/~millerp/

       Portions  of  this program are derived from sources from other people, sometimes with liberal copyrights,
       and sometimes in the public domain.  These include:

       Dan Bernstien
               See common/fp/README for details.

       Gary S Brown.
               See common/fp/crc32.c for details.

       RSA Data Security, Inc.
               See common/fp/md5.c for details.

       Xerox Corporation
               See common/fp/snefru.c for details.

       In addition to the above copyright holders, there have been numerous authors and  contributors,  see  the
       named files for details.  Files names are relative to the root of the aegis distribution.

                                                Reference Manual                                         aefp(1)