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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <html>
<head>
<title>cpipe --- counting pipe</title>
<!-- $Revsion$, $Date: 2001/12/09 10:35:41 $ -->
</head>
<body>
<h1>cpipe --- counting pipe</h1>
<p>Did you ever want to know how fast your <code>tar</code> is or how
much data it has transferred already. How about using
<code>socket</code> or <code>nc</code> to copy files either with or
without compression over a fast network connection, which one is
faster?</p>
<p>If you want to know the answer, use <code>cpipe</code> as a totally
<em>unscientific</em> approach to measure throughput.
<code>Cpipe</code> copies its standard input to its standard output
while measuring the time it takes to read an input buffer and write an
output buffer. Statistics of average throughput and the total amount
of bytes copied are printed to the standard error output.</p>
<h2>Example</h2>
<p>
The command
<blockquote>
<code>
tar cCf / - usr | <font color=red>cpipe</font> -vr -vw -vt > /dev/null
</code>
</blockquote>
results in an output like
<blockquote><pre>
...
in: 19.541ms at 6.4MB/s ( 4.7MB/s avg) 2.0MB
out: 0.004ms at 30.5GB/s ( 27.1GB/s avg) 2.0MB
thru: 19.865ms at 6.3MB/s ( 4.6MB/s avg) 2.0MB
...</pre>
</blockquote>
</p>
<p>
The first column shows the times it takes to handle one buffer
of data (128kB by default). The read-call took 19.541ms, the
write-call to /dev/null took just 0.004ms and from the start of
the read to the end of write, it took 19.865ms.
</p>
<p>
The second column shows the result of dividing the buffer size
(128kB by default) by the times in the first column.
</p>
<hr>
<p>The current version is |VERSION|. You may want to read the
list of recent <a href="CHANGES">CHANGES</a>. The software
<font color="red">can be downloaded from</font>
<a href="http://developer.berlios.de/projects/cpipe/">
<img align=center
src="http://developer.berlios.de/sflogo.php?group_id=226&type=1"
width="118" height="52" border="0" alt="BerliOS Logo">
</a>
</p>
</hr>
</body>
</html>
|
