Why does the 'tail' command return the whole file content when using -c+1 or -c-1?
<p>As the question itself, I cannot find out why <code>tail</code> acts that way.
I have a file named <code>myfile.txt</code> and its content is:</p>

<pre><code> firstline
 secondline
 thirdline
</code></pre>

<p>So when I use:</p>

<pre><code> tail -c-1 myfile.txt
</code></pre>

<p>or</p>

<pre><code> tail -c+1 myfile.txt
</code></pre>

<p>it outputs:</p>

<pre><code> firstline
 secondline
 thirdline
</code></pre>

<p><code>man tail</code>:</p>

<blockquote>
  <p>-c, --bytes = [+] NUM<br>
   output  the  last  NUM  bytes; or use -c +NUM to output starting
   with byte NUM of each file</p>
</blockquote>