From: Matthew Moss <matthew.moss@...>
Date: 2008-07-26T02:22:10+09:00
Subject: [QUIZ] hexdump (#171)

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## hexdump (#171)

_Quiz idea provided by Robert Dober._

This week's quiz should be quick and easy for experienced Rubyists,
and a good lesson for beginners. Your task this week is to write a
utility that outputs a hex dump of the input.

There are a number of hex dump utilities in existence, that go by the
names `hd`, `od`, `hexdump`... I'm sure there are more. Pick one you'd
like to reproduce: If you're on any variety of Unix or BSD (including
Mac OS X), you can get man pages from the command-line to see how they
work. On Windows, if you don't have one installed, you can check out
this [man page for hexdump][1] and use that as a model.

You are not required to implement all the various command-line
switches, but I should be able to run your script on a file and, as a
minimum, see output resembling this (view with fixed-width font for
best results):

    0000000 6573 2074 6c68 0a73 7973 746e 7861 6f20
    0000010 0a6e 6f63 6f6c 7372 6863 6d65 2065 6564
    0000020 6573 7472 0a0a 6573 2074 7865 6170 646e
    0000030 6174 0a62 6573 2074 6174 7362 6f74 3d70
    0000040 0a32 6573 2074 6873 6669 7774 6469 6874
    0000050 323d 220a 6573 2074 6574 7478 6977 7464
    0000060 3d68 3836 0a0a 2022 2051 6f63 6d6d 6e61
    0000070 2064 6f74 7220 6665 726f 616d 2074 6170
    0000080 6172 7267 7061 7368 6120 646e 6c20 7369
    0000090 2e74 6e0a 6f6e 6572 616d 2070 2051 7167
    00000a0 0a7d 0a0a
    00000a4

Your submission should accept input either from a named file (part of
the command-line arguments) or from standard input if no filename is
provided.

Finally, when submitting, make sure to describe what existing hex dump
program you are emulating/reproducing (if any), and what arguments to
your script are needed, if any, to produce the basic output above.


[1]: http://unixhelp.ed.ac.uk/CGI/man-cgi?hexdump+1


-- 
Matthew Moss <matthew.moss@gmail.com>