012541e375
git-svn-id: svn+ssh://atelier.inf.usi.ch/home/bevilj/group-1@186 a672b425-5310-4d7a-af5c-997e18724b81
56 lines
1.9 KiB
HTML
56 lines
1.9 KiB
HTML
---
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layout: page
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category-title: Intermediate commands
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category-page: intermediate
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tags: base64 representation
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author: Gianmarco De Vita
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title: Base64
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previous-page:
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next-page:
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---
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<p><i>Base64</i> is an encoding system that allows the translation of binary
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data into ASCII text strings, basing upon 64 different ASCII characters.
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Each <i>Base64</i> digit represents exactly 6 bits of data so, for example,
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six bytes (a total of 48 bits) can be represented by eight <i>Base64</i> digits.</p>
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<p>By writing the command <code>base64</code> you can encode and decode Base64 data.
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The command follows the structure:</p>
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<pre>
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Device-name:Current-position username$ base64 [flag] [-i input item] [-o output item]
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</pre>
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<h3>Defining input and output files</h3>
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<p>In this case, flag such as <code>-i</code> and <code>-o</code> are fundamental
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to define respectevely from which file take the stream and into which to store
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the result. Naturally, the path and the name of the files must be specified.</p>
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<pre>
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Device-name:Current-position username$ base64 -i path/input.file -o path/output.file
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</pre>
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<h3>Insert line breaks</h3>
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<p>Using the <code>-b</code> (which stands for <i>break</i>) flag followed by a
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number, line breaks are added every specified "number" characters.</p>
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<pre>
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Device-name:Current-position username$ base64 -b number path/input.file path/output.file
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</pre>
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<p>By leaving the number field empty, an unbroken stream will be generated.</p>
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<h3>Decode Base64</h3>
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<p>Using the <code>-D</code> flag (which stands for decode), you obtain as
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output the input message decoded into binary data.</p>
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<pre>
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Device-name:Current-position username$ base64 -D [-i input item] [-o output item]
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</pre>
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<h3>Summarize the tools</h3>
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<p>Using the <code>-h</code> (which stands for <i>help</i>) a short paragraph
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in which are listed the flags with the respective paragraph will be displayed.</p>
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<pre>
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Device-name:Current-position username$ base64 -h
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</pre>
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