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http://en.wikipedia.org/wiki/Morse_code

Morse code is a character encoding for transmitting telegraphic information,
using standardized sequences of short and long elements to represent the
letters, numerals, punctuation and special characters of a given message. The
short and long elements can be formed by sounds, marks, or pulses, in on off
keying and are commonly known as "dots" and "dashes" or "dits" and "dahs".

    A  .-          N  -.          1  .----       .  .-.-.-
    B  -...        O  ---         2  ..---       ,  --..--
    C  -.-.        P  .--.        3  ...--       ?  ..--..
    D  -..         Q  --.-        4  ....-       (  -.--.
    E  .           R  .-.         5  .....       )  -.--.-
    F  ..-.        S  ...         6  -....       -  -....-
    G  --.         T  -           7  --...       "  .-..-.
    H  ....        U  ..-         8  ---..       _  ..--.-
    I  ..          V  ...-        9  ----.       '  .----.
    J  .---        W  .--         0  -----       :  ---...
    K  -.-         X  -..-        /  -..-.       ;  -.-.-.
    L  .-..        Y  -.--        +  .-.-.       $  ...-..-
    M  --          Z  --..        =  -...-

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Write a program that translates a text file into morse code, and can also
translate a morse code file back into text.

  perl morse.pl   encode original.txt morse.txt
  perl morse.pl unencode morse.txt    output.txt

There should be no difference between the original and the unencoded
output produced by the program, except that case should be folded to
upper case.

Given the following input (original.txt):

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This is my string Samuel
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And run as:

  perl morse.pl encode original.txt morse.txt

The program should produce something like the following morse-code file:

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-, ...., .., ...,  , .., ...,  , --, -.--,  , ..., -, .-., .., -., --.,  , ..., .-, --, ..-, ., .-.., 
, 
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Then, when run as:

  perl morse.pl unencode morse.txt output.txt

It should produce the input (as upper case):

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THIS IS MY STRING SAMUEL
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