rks</h2>

<p>
Pauses until a string, which satisfies a condition, is received from the host, or until the timeout occurs.
</p>

<p>
The condition is:<br>
The length of the string is &lt;len&gt;, and the string contains the &lt;sub-string&gt; beginning at the &lt;pos&gt;th(1-origin) character.<br>
This command confirms whether the string is matched every time &lt;len&gt; byte is received. <br>
For example, if &lt;sub-string&gt; is "def" and &lt;len&gt; is 9 and &lt;pos&gt; is 4, the string "abcdefg