c4b3b2e4ef
git-svn-id: svn+ssh://atelier.inf.usi.ch/home/bevilj/group-1@248 a672b425-5310-4d7a-af5c-997e18724b81
42 lines
1.3 KiB
HTML
42 lines
1.3 KiB
HTML
---
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layout: page
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author: Agostino Monti
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category-page: advanced
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category-title: Advanced commands
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tags: head tail text file
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title: head and tail
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---
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The <code>head</code> command reads the first few lines of any text given to it as an input
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and writes them to standard output.<br>
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If more than one input file is provided, head will return the first ten lines
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from each file, precede each set of lines by the name of the file and separate
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each set of lines by one vertical space.
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<pre>
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head [flags] [file1] [file2] ...
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</pre>
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The <code>tail</code> command is similar to the <code>head</code> command
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except that it reads the final lines in files rather than the first lines.
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<pre>
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tail [flags] [file1] [file2] ...
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</pre>
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<h3>Flags</h3>
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<ul>
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<li><b>-n</b>: can be used followed by number, which indicates the number of
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lines desired in the output. This flag can be used without <i>n</i>: the hyphen and the
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number (with no intervening space) are enough to tell head how many lines to return.
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<pre>
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head -n15 file1.txt <br>
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head -n 15 file1.txt <br>
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head -15 file1.txt</pre>
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</li>
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<li><b>-c</b>: similar to <i>-n</i> with the only difference being that the number stands for
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bytes instead of the number of lines and the fact that it can't be used without explicitly
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typing the <i>-c</i>.
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</li>
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</ul>
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