NuttShell.html

  <td>
    <a name="cmdsleep"><h2>2.24 Wait for Seconds (sleep)</h2></a>
  </td>
  </tr>
</table>

<a <p><b>Command Syntax:</b></p>
<ul><pre>
sleep &lt;sec&gt;
</pre></ul>
<p>
  <b>Synopsis</b>.
  Pause execution (sleep) for <code>&lt;sec&gt;</code> seconds.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="cmdunmount"><h2>2.25 Unmount a File System (umount)</h2></a>
  </td>
</tr>
</table>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="cmdunset"><h2>2.26 Unset an Environment Variable (unset)</h2></a>
  </td>
  </tr>
</table>

<a <p><b>Command Syntax:</b></p>
<ul><pre>
unset &lt;name&gt;
</pre></ul>
<p>
  <b>Synopsis</b>.
  Remove the value associated with the environment variable
  <code>&lt;name&gt;.  Example:
</p>
<ul><pre>
nsh&gt; echo $foobar
foovalue
nsh&gt; unset foobar
nsh&gt; echo $foobar

nsh&gt;
</pre></ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="cmdusleep"><h2>2.27 Wait for Microseconds (usleep)</h2></a>
  </td>
  </tr>
</table>

<a <p><b>Command Syntax:</b></p>
<ul><pre>
usleep &lt;usec&gt;
</pre></ul>
<p>
  <b>Synopsis</b>.
  Pause execution (sleep) of <code>&lt;usec&gt;</code> microseconds.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="configuration"><h1>3.0 Configuration Settings</h1></a>
  </td>
  </tr>
</table>

<p>
  The availability of the above commands depends upon features that
  may or may not be enabled in the NuttX configuration file.  The 
  following <a href="#cmddependencies">table</a> indicates the dependency of each command on NuttX
  configuration settings.  General configuration settings are discussed
  in the <a href="NuttxPortingGuide.html">NuttX Porting Guide.</a>
  Configuration settings specific to NSH as discussed at the <a href="#nshconfiguration">bottom</a> of this document.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="cmddependencies"><h2>3.1 Command Dependencies on Configuration Settings</h2></a>
  </td>
  </tr>
</table>

<center><p>Table. Command Dependencies on Configuration Settings</p>
<table width="100%">
  <tr bgcolor="#e4e4e4">
    <th align="left" width="25%">Command</th>
    <th align="left">Depends on Configuration</th>
  </tr>
  <tr>
    <td><b><code>[</code></b></td>
    <td>!<code>CONFIG_EXAMPLES_NSH_DISABLESCRIPT</code></td>
  </tr>
  <tr>
    <td><b><code>cat</code></b></td>
    <td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>cd</code></b></td>
    <td>!<code>CONFIG_DISABLE_ENVIRON</code> && <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>cp</code></b></td>
    <td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>echo</code></b></td>
    <td><br></td>
  </tr>
  <tr>
    <td><b><code>exec</code></b></td>
    <td><br></td>
  </tr>
  <tr>
    <td><b><code>exit</code></b></td>
    <td><br></td>
  </tr>
  <tr>
    <td><b><code>help</code></b></td>
    <td><br></td>
  </tr>
  <tr>
    <td><b><code>ifconfig</code></b></td>
    <td><code>CONFIG_NET</code></td>
  </tr>
  <tr>
    <td><b><code>ls</code></b></td>
    <td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>mb,mh,mw</code></b></td>
    <td><br></td>
  </tr>
  <tr>
    <td><b><code>mem</code></b></td>
    <td><br></td>
  </tr>
  <tr>
    <td><b><code>mkdir</code></b></td>
    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> && <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>mkfatfs</code></b></td>
    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> && <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 && <code>CONFIG_FS_FAT</code></td>
  </tr>
  <tr>
    <td><b><code>mkfifo</code></b></td>
    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> && <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>mount</code></b></td>
    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> && <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 && <code>CONFIG_FS_FAT</code></td>
  </tr>
  <tr>
    <td><b><code>ping</code></b></td>
    <td><code>CONFIG_NET</code> &amp;&amp; <code>CONFIG_NET_ICMP &amp;&amp;</code> <code>CONFIG_NET_ICMP_PING</code>  &amp;&amp; !<code>CONFIG_DISABLE_CLOCK</code> &amp;&amp; !<code>CONFIG_DISABLE_SIGNALS</code></td>
  </tr>
  <tr>
    <td><b><code>ps</code></b></td>
    <td><br></td>
  </tr>
  <tr>
    <td><b><code>pwd</code></b></td>
    <td>!<code>CONFIG_DISABLE_ENVIRON</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>rm</code></b></td>
    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>rmdir</code></b></td>
    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
  </tr>
  <tr>
    <td><b><code>set</code></b></td>
    <td>!<code>CONFIG_DISABLE_ENVIRON</code></td>
  </tr>
  <tr>
    <td><b><code>sh</code></b></td>
    <td><code>CONFIG_NFILE_DESCRIPTORS &gt; 0 &amp;&amp; <code>CONFIG_NFILE_STREAMS &gt; 0 &amp;&amp; !<code>CONFIG_EXAMPLES_NSH_DISABLESCRIPT</code></td>
  </tr>
  <tr>
    <td><b><code>sleep</code></b></td>
    <td>!<code>CONFIG_DISABLE_SIGNALS</code></td>
  </tr>
  <tr>
    <td><b><code>test</code></b></td>
    <td>!<code>CONFIG_EXAMPLES_NSH_DISABLESCRIPT</code></td>
  </tr>
  <tr>
    <td><b><code>umount</code></b></td>
    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_FS_FAT</code></td>
  </tr>
  <tr>
    <td><b><code>unset</code></b></td>
    <td>!<code>CONFIG_DISABLE_ENVIRON</code></td>
  </tr>
  <tr>
    <td><b><code>usleep</code></b></td>
    <td>!<code>CONFIG_DISABLE_SIGNALS</code></td>
  </tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="nshconfiguration"><h2>3.2  NSH-Specific Configuration Settings</h2></a>
  </td>
  </tr>
</table>

<p>
  The behavior of NSH can be modified with the following settings in
  the <code>configs/&lt;board-name&gt;/defconfig</code> file:
</p>

<center><table width="100%">
  <tr bgcolor="#e4e4e4">
    <th align="left" width="25%">Configuration</th>
    <th align="left">Description</th>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_FILEIOSIZE</code></b></td>
    <td>
      Size of a static I/O buffer used for file access (ignored if
      there is no filesystem).
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_STRERROR</code></b></td>
    <td>
      strerror(errno) makes more readable output but strerror() is
      very large and will not be used unless this setting is <i>y</i>
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_LINELEN</code></b></td>
    <td>
      The maximum length of one command line and of one output line.
      Default: 80
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_STACKSIZE</code></b></td>
    <td>
      The stack size to use when spawning new threads or tasks.  Such
      new threads are generated when a command is executed in background
      or as new TELNET connections are established.
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_NESTDEPTH</code></b></td>
    <td>
      The maximum number of nested <a href="#conditional"><code>if-then[-else]-fi</code></a> sequences that
      are permissable.  Default: 3
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_DISABLESCRIPT</code></b></td>
    <td>
      This can be set to <i>y</i> to suppress support for scripting.  This
      setting disables the <a href="#cmdsh"><code>sh</code></a>, <a href="#cmdtest"><code>test</code></a>, and <a href="#cmtest"><code>[</code></a> commands and the
      <a href="#conditional"><code>if-then[-else]-fi</code></a> construct.  This would only be set on systems
      where a minimal footprint is a necessity and scripting is not.
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_DISABLEBG</code></b></td>
    <td>
      This can be set to <i>y</i> to suppress support for background
      commands.  This setting disables the <a href="#cmdoverview"><code>nice</code></a> command prefix and
      the <a href="#cmdoverview"><code>&amp;</code></a> command suffix.  This would only be set on systems
      where a minimal footprint is a necessity and background command execution is not.
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_CONSOLE</code></b></td>
    <td>
      If <code>CONFIG_EXAMPLES_NSH_CONSOLE</code>is set to <i>y</i>, then a serial
      console front-end is selected.
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_TELNET</code></b></td>
    <td>
      If <code>CONFIG_EXAMPLES_NSH_TELNET</code> is set to <i>y</i>, then a TELENET
      server front-end is selected.  When this option is provided,
      you may log into NuttX remotely using telnet in order to
      access NSH.
    </td>
  </tr>
</table>

<p>
  One or both of <code>CONFIG_EXAMPLES_NSH_CONSOLE</code> and <code>CONFIG_EXAMPLES_NSH_TELNET</code>
  must be defined.  If <code>CONFIG_EXAMPLES_NSH_TELNET</code> is selected, then there some
  other configuration settings that apply:
</p>

<center><table width="100%">
  <tr bgcolor="#e4e4e4">
    <th align="left" width="25%">Configuration</th>
    <th align="left">Description</th>
  </tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_IOBUFFER_SIZE</code></b></td>
    <td>
      Determines the size of the I/O buffer to use for sending/
      receiving TELNET commands/reponses
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_DHCPC</code></b></td>
    <td>
      Obtain the the IP address via DHCP.
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_IPADDR</code></b></td>
    <td>
      If <code>CONFIG_EXAMPLES_NSH_DHCPC</code> is NOT set, then the static IP
      address must be provided.
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_DRIPADDR</code></b></td>
    <td>
      Default router IP address
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_NETMASK</code></b></td>
    <td>
      Network mask
    </td>
  </tr>
  <tr>
    <td><br><code>CONFIG_EXAMPLES_NSH_NOMAC</code></b></td>
    <td>
      Set if your ethernet hardware has no built-in MAC address.
      If set, a bogus MAC will be assigned.
    </td>
  </tr>
</table>

</body>
</html>