2018-11-09 15:09:37 +00:00
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<body>
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2018-11-10 10:26:32 +00:00
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<!-- Echo command text -->
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<h3>Echo</h3>
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<p>This command print as output its entire argument on the command-line.<br>
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It could be used with variables, like in the following example:</p>
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<hr>
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<p>$ example:"this is an example"</p>
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<br>
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<p>$ <b>echo</b> $example</p>
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<p>this is an example</p>
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<hr>
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<br>
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<!-- Cat command text -->
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<h3>Cat</h3>
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<p>This command prints the content of a certain file as an output on the command-line.</p>
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<p>As example, we could imagine a simple text file in pages named "Hello", which contains the line "Hello World".<br>
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So, our command example will look like this:</p>
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<hr>
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<p>$ pages Hello</p>
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<p>$ <b>cat</b> Hello<br>
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Hello World</p>
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<hr>
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<br>
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<!-- NOTE: Grep command text -->
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<h3>Grep</h3>
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<p>This one behaves very similarly to the previus one, but in this case it prints only the lines matching a certain pattern.<br>
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In this we could imagine a certain text file "animals", which contains a list of animal-names.</p>
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<p>If we want to select only the animals whose name begins with the letter "d", we will write this:<br>
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<hr>
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<p>$ grep d animals<br>
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Deer<br>
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Dog<br>
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Dolphin<br>
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...
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<br>
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<hr>
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<br>
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2018-11-09 15:09:37 +00:00
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</body>
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</html>
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