73 lines
3.2 KiB
HTML
73 lines
3.2 KiB
HTML
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---
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layout: page
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author: Alessandro Luini
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category-page: advanced
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category-title: Advanced commands
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tags: Vi advanced text editor
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title: Vi
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---
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<p>The default editor that comes with the UNIX operating system is called
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vi (visual editor).</p>
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<br><br>
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<p>The UNIX vi editor is a full screen editor and has two modes of
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operation:</p>
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<br><br>
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<ol><li>Command mode commands which cause action to be taken on the file,
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and</li>
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<li>Insert mode in which entered text is inserted into the file.</li>
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</ol>
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<br><br>
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<p>In the command mode, every character typed is a command that does
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something to the text file being edited; a character typed in the
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command mode may even cause the vi editor to enter the insert mode.
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In the insert mode, every character typed is added to the text in the
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file; pressing the {Esc} (Escape) key turns off the Insert mode.</p>
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<p>While there are a number of vi commands, just a handful of these
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is usually sufficient for beginning vi users. To assist such users,
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this Web page contains a sampling of basic vi commands. The most
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basic and useful commands are marked with an asterisk (* or star)
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in the tables below. With practice, these commands should become
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automatic.</p>
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<p>Both UNIX and vi are <b>case-sensitive</b>. Be sure not to use a
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capital letter in place of a lowercase letter; the
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results will not be what you expect.</p><br><br>
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<h3>How to start <code> vi </code>
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</h3>
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<p>To use vi on a file, type in vi filename. If the file named
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filename exists, then the first page (or screen) of the file
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will be displayed; if the file does not exist, then an empty
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file and screen are created into which you may enter text.</p>
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<pre>vi filename.txt</pre>
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<p>To edit filename starting at line 1</p>
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<br><br>
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<h3>How to exit <code>vi</code></h3>
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<p>Usually the new or modified file is saved when you leave vi.
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However, it is also possible to quit vi without saving the file.
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</p>
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<p>The cursor moves to bottom of screen whenever a colon (:) is
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typed. This type of command is completed by hitting the
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<Return> (or <Enter>) key.<br><br>
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<pre>:q<Return></pre>
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<p>quit (or exit). <code>vi</code></p>
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<pre>:x<Return></pre>
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<p>quit vi, writing out modified file to
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file named in original invocationt modified file to file
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named in original </p>
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<pre>:wq<Return></pre>
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<p>quit vi, writing out modified file to file named in
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original invocation.</p>
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<pre>:q!<Return></pre>
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<p>quit vi even though latest changes have not been
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saved for this vi call</p>
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<h3>Flags</h3>
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<h4>-r:</h4>
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<p>Use -r to recover filename that was being edited when system
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crashed.</p>
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<pre>vi -r filename.txt</pre>
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