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git-svn-id: svn+ssh://atelier.inf.usi.ch/home/bevilj/group-1@254 a672b425-5310-4d7a-af5c-997e18724b81
88 lines
2.5 KiB
HTML
88 lines
2.5 KiB
HTML
---
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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: advanced text editor hell quit help escape sos
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title: vi
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previous-page: pages/cmd/advanced/tr.html
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next-page: pages/cmd/advanced/wc.html
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---
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The default editor that comes with the UNIX operating system is called
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<code>vi</code> (visual editor).<br>
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The UNIX vi editor is a full screen editor and has two modes of operation:
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<ol>
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<li>Command mode commands which cause action to be taken on the file</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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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.<br>
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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.<br>
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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.<br>
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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.<br>
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<h3>How to start <code>vi</code></h3>
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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>
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vi filename.txt
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</pre>
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<h3>How to exit <code>vi</code></h3>
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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.<br>
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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>
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<pre>
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:q
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</pre>
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Quit vi without saving
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<pre>
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:x
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</pre>
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Quit vi, writing out modified file to
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file named in original invocationt modified file to file named in origin.
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<pre>
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:wq
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</pre>
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Quit vi, writing out modified file to file named in original invocation.
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<pre>
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:q!
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</pre>
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Quit vi even though latest changes have not been saved for this vi call.
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<h3>Recover from a crash</h3>
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Open vi using the <code>-r</code> flag to recover a file that was being edited when a crash
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happened.
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