XD
                      Hexadecimal dump and load

                            by John Walker
                 Revision 1  --  December 30th, 1991

This program was created  out  of  exasperation  with  the  Unix  "od"
program  which,  notwithstanding  its  acronym  of  "octal  dump" will
happily make hexadecimal dumps of files but, in tribute to  the  past,
refuses to display file addresses as anything other than octal.

XD is a hexadecimal file dump program without pretensions of grandeur.
It  dumps files as hex bytes, optionally showing the same bytes as ISO
characters,  with  non-printing  characters  (defined according to ISO
8859/1 Latin-1) rendered as periods.  File addresses are shown as  hex
numbers without leading zeroes.

XD  has  a  few  more little tricks up its sleeve.  If you specify the
"-l" option, XD will *read* a dump file in the same format  it  writes
and create a binary file from the hex data.  This allows you to dump a
binary file with XD, edit it with your  favourite  text  editor,  then
make  a  new  binary  file containing whatever changes you made.  When
creating a binary file, XD normally assumes you've only  changed  data
in  place  (neither  expanding  nor contracting the file) and verifies
file addresses to guarantee  this.   However,  if  you  set  the  "-s"
(stream)  option, file addresses are ignored and you're free to insert
or delete bytes at will.  These options effectively turn your existing
text  editor  into a binary file editor without requiring you to learn
any new commands.

Finally, the "-d" option reads a binary file and emits  a  C  language
data declaration which contains the data from the file.  This is handy
when you wish to embed binary data within programs.

XD is written to be as portable as possible.  It does assume that file
I/O  is not subjected to end of line translation; if you're porting it
to a  system  such  as  MS-DOS  which  requires  binary  files  to  be
explicitly  declared,  you'll  have  to  add  code appropriate to your
compiler.

AUTHOR
            John Walker
            Autodesk Neuchâtel
            Avenue des Champs-Montants 14b
            CH-2074 MARIN
            Switzerland
            Usenet: kelvin@Autodesk.com
            Fax:    038/33 88 15
            Voice:  038/33 76 33

This program is in the public domain: "Do what thou wilt shall be  the
whole  of  the  law".   I'd  appreciate receiving any bug fixes and/or
enhancements,  which  I'll  incorporate  in  future  versions  of  the
program.   Please leave the original attribution information intact so
that credit and blame may be properly apportioned.