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<html>
<head>
<title>NuttShell</title>
</head>
<body background="backgd.gif">
<hr><hr>
<table width ="100%">
<tr align="center" bgcolor="#e4e4e4">
<td>
<h1><big><font color="#3c34ec"><i>NuttShell (NSH)</i></font></big></h1>
<p>Last Updated: March 6, 2012</p>
</td>
</tr>
</table>
<hr><hr>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>Table of Contents</h1>
</td>
</tr>
</table>
<center><table width ="80%">
<tr>
<td>
<table>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#overview">1.0 Overview</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#frontend">1.1 Console/NSH Front End</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdoverview">1.2 Command Overview</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#conditional">1.3 Conditional Command Execution</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#builtinvars">1.4 Built-In Variables</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#currentwd">1.5 Current Working Directory</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#environvars">1.6 Environment Variables</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#startupscript">1.7 NSH Start-Up Script</a>
</td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#commands">2.0 Commands</a>.
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdtest">2.1 Evaluate Expression (test)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdcat">2.2 Concatenate Files (cat)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdcd">2.3 Change Current Working Directory (cd)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdcp">2.4 Copy Files (cp)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmddate">2.5 Show or set the date and time (date)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmddd">2.6 Copy and Convert Files (dd)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdecho">2.7 Echo Strings and Variables (echo)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdexec">2.8 Execute User Code (exec)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdexit">2.9 Exit NSH (exit)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdfree">2.10 Show Memory Manager Status (free)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdget">2.11 Get File Via TFTP (get)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdhelp">2.12 Show Usage Command Usage (help)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdifconfig">2.13 Show Network Configuration (ifconfig)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdkill">2.14 Send a signal to a task (kill)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdlosetup">2.15 Setup/teardown the Loop Device (losetup)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdls">2.16 List Directory Contents (ls)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdmbhw">2.17 Access Memory (mb, mh, and mw)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdps">2.18 Show Current Tasks and Threads (ps)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdmkdir">2.19 Create a Directory (mkdir)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdmkfatfs">2.20 Create a FAT Filesystem (mkfatfs)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdmkfifo">2.21 Create a FIFO (mkfifo)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdmkrd">2.22 Create a RAMDISK (mkrd)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdmount">2.23 Mount a File System (mount)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdping">2.24 Check Network Peer (ping)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdput">2.25 Send File Via TFTP (put)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdpwd">2.26 Show Current Working Directory (pwd)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdrm">2.27 Remove a File (rm)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdrmdir">2.28 Remove a Directory (rmdir)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdset">2.29 Set an Environment Variable (set)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdsh">2.30 Execute an NSH Script (sh)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdsleep">2.31 Wait for Seconds (sleep)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdunmount">2.32 Unmount a File System (umount)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdunset">2.33 Unset an Environment Variable (unset)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdusleep">2.34 Wait for Microseconds (usleep)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdwget">2.35 Get File Via HTTP (wget)</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmdxd">2.36 Hexadecimal Dump (xd)</a>
</td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#configuration">3.0 Configuration Settings</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#cmddependencies">3.1 Command Dependencies on Configuration Settings</a>
</td>
</tr>
<tr>
<td><br></td>
<td>
<a href="#nshconfiguration">3.2 NSH-Specific Configuration Settings</a>
</td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#index">Index</a>
</td>
</table>
</td>
</tr>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="overview"><h1>1.0 Overview</h1></a>
</td>
</tr>
</table>
<p>
The <code>apps/nshlib</code> sub-directory contains the NuttShell (NSH)
library.
This library can easily to linked to produce a NSH application (See as an example <code>apps/nshlib</code>).
NSH is a simple shell application for NuttX.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="frontend"><h2>1.1 Console/NSH Front End</h2></a>
</td>
</tr>
</table>
<p>
Using settings in the configuration file, NSH may be configured to
use either the serial stdin/out or a telnet connection as the console
or BOTH. When NSH is started, you will see the following welcome on
either console:
<ul><pre>
NuttShell (NSH)
nsh&gt;
</pre></ul>
<code>nsh&gt;</code> is the NSH prompt and indicates that you may enter a command
from the console.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdoverview"><h2>1.2 Command Overview</h2></a>
</td>
</tr>
</table>
<p>
<b>Simple, Re-directed, and Background Commands</b>.
The NuttShell (NSH) is a simple shell application.
NSH supports the following commands forms:
</p>
<ul><table>
<tr>
<td>Simple command:</td>
<td><code>&lt;cmd&gt;</code></td>
</tr>
<tr>
<td>Command with re-directed output:</td>
<td><code>
&lt;cmd&gt; &gt; &lt;file&gt;<br>
&lt;cmd&gt; &gt;&gt; &lt;file&gt;
</code></td>
</tr>
<tr>
<td>Background command:</td>
<td><code>&lt;cmd&gt; &amp;</code></td>
</tr>
<tr>
<td>Re-directed background command:</td>
<td><code>
&lt;cmd&gt; &gt; &lt;file&gt; &amp;<br>
&lt;cmd&gt; &gt;&gt; &lt;file&gt; &amp;
</code></td>
</tr>
</table></ul>
<p>Where:</p>
<ul><table>
<tr>
<td><code>&lt;cmd&gt;</code></td>
<td>
is any one of the simple commands listed later.
</td>
</tr>
<tr>
<td><code>&lt;file&gt;</code></td>
<td>
is the full or relative path to any writable object
in the filesystem name space (file or character driver).
Such objects will be referred to simply as files throughout
this document.
</td>
</tr>
</table></ul>
<p>
<b><big><code>nice</code></big>'d Background Commands</b>
NSH executes at the mid-priority (128). Backgrounded commands can
be made to execute at higher or lower priorities using <code>nice</code>:
</p>
<ul><code>
[nice [-d &lt;niceness&gt;&gt;]] &lt;cmd&gt; [&gt; &lt;file&gt;|&gt;&gt; &lt;file&gt;] [&amp;]
</code></ul>
<p>
Where <code>&lt;niceness&gt;</code> is any value between -20 and 19 where lower
(more negative values) correspond to higher priorities.
The default niceness is 10.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="conditional"><h2>1.3 Conditional Command Execution</h2></a>
</td>
</tr>
</table>
<p>
An <code>if-then[-else]-fi</code> construct is also supported in order to
support conditional execution of commands. This works from the
command line but is primarily intended for use within NSH scripts
(see the <a href="#cmdsh"><code>sh</code></a> commnd). The syntax is as follows:
</p>
<ul><pre>
if &lt;cmd&gt;
then
[sequence of &lt;cmd&gt;]
else
[sequence of &lt;cmd&gt;]
fi
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="builtinvars"><h2>1.4 Built-In Variables</h2></a>
</td>
</tr>
</table>
<ul><table>
<tr>
<td valign="top"><b><code>$?</code></b></td>
<td>
The result of the last simple command execution.
On backgrounded commands, this variable holds only the result of spawning the background command.
</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="currentwd"><h2>1.5 Current Working Directory</h2></a>
</td>
</tr>
</table>
<p>
<b><code>cd</code> and <code>pwd</code></b>.
All path arguments to commands may be either an absolute path or a
path relative to the current working directory. The current working
directory is set using the <a href="#cmdcd"><code>cd</code></a> command and can be queried either
by using the <a href="#cmdpwd"><code>pwd</code></a> command or by
using the <a href="#cmdecho"><code>echo</code></a> <a href="#environvars"><code>$PWD</code></a>
command.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="environvars"><h2>1.6 Environment Variables</h2></a>
</td>
</tr>
</table>
<p>
<b>Environment Variables:</b>
</p>
<ul><table>
<tr>
<td><b><code>PWD</code></b></td><td>The current working directory</td>
</tr>
<tr>
<td><b><code>OLDPWD</code></b></td><td>The previous working directory</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="startupscript"><h2>1.7 NSH Start-Up Script</h2></a>
</td>
</tr>
</table>
<p>
<b>NSH Start-Up Script</b>.
NSH supports options to provide a start up script for NSH. In general
this capability is enabled with <code>CONFIG_NSH_ROMFSETC</code>, but has
several other related configuration options as described with the
<a href="#nshconfiguration">NSH-specific configuration settings</a>.
This capability also depends on:
<ul>
<li><code>CONFIG_DISABLE_MOUNTPOINT</code> not set
<li><code>CONFIG_NFILE_DESCRIPTORS</code> &lt; 4
<li><code>CONFIG_FS_ROMFS</code> enabled
</ul>
</p>
<p>
<b>Default Start-Up Behavior</b>.
The implementation that is provided is intended to provide great flexibility
for the use of Start-Up files. This paragraph will discuss the general
behavior when all of the configuration options are set to the default
values.
</p>
<p>
In this default case, enabling <code>CONFIG_NSH_ROMFSETC</code> will cause
NSH to behave as follows at NSH startup time:
<ul>
<li>
NSH will create a read-only RAM disk (a ROM disk), containing a tiny
ROMFS filesystem containing the following:
<ul><pre>
`--init.d/
`-- rcS
</pre></ul>
Where rcS is the NSH start-up script.
</li>
<li>
NSH will then mount the ROMFS filesystem at <code>/etc</code>, resulting in:
<ul><pre>
|--dev/
| `-- ram0
`--etc/
`--init.d/
`-- rcS
</pre></ul>
</li>
<li>
By default, the contents of rcS script are:
<ul><pre>
# Create a RAMDISK and mount it at XXXRDMOUNTPOUNTXXX
mkrd -m 1 -s 512 1024
mkfatfs /dev/ram1
mount -t vfat /dev/ram1 /tmp
</pre></ul>
</li>
<li>
NSH will execute the script at <code>/etc/init.d/rcS</code> at start-up (before the
first NSH prompt. After execution of the script, the root FS will look
like:
<ul><pre>
|--dev/
| |-- ram0
| `-- ram1
|--etc/
| `--init.d/
| `-- rcS
`--tmp/
</pre></ul>
</li>
</ul>
</p>
<p>
<b>Modifying the ROMFS Image</b>.
The contents of the <code>/etc</code> directory are retained in the file <code>apps/nshlib/nsh_romfsimg.h</code> OR, if <code>CONFIG_NSH_ARCHROMFS</code> is defined, <code>include/arch/board/rcs.template</code>).
In order to modify the start-up behavior, there are three things to study:
<ol>
<li>
<b>Configuration Options.</b>
The additional <code>CONFIG_NSH_ROMFSETC</code> configuration options
discussed with the other <a href="#nshconfiguration">NSH-specific configuration settings</a>.
</li>
<li>
<p>
<b><code>tools/mkromfsimg.sh</code> Script</b>.
The script <code>tools/mkromfsimg.sh</code> creates <code>nsh_romfsimg.h</code>.
It is not automatically executed. If you want to change the
configuration settings associated with creating and mounting
the <code>/tmp</code> directory, then it will be necessary to re-generate
this header file using the <code>tools/mkromfsimg.sh</code> script.
</p>
<p>
The behavior of this script depends upon three things:
<ul>
<li>The configuration settings then installed configuration.
<li>The <code>genromfs</code> tool (available from <a href="http://romfs.sourceforge.net">http://romfs.sourceforge.net</a>).
<li>The file <code>apps/nshlib/rcS.template</code>
(OR, if <code>CONFIG_NSH_ARCHROMFS</code> is defined <code>include/arch/board/rcs.template</code>.
</ul>
</p>
</li>
<li>
<b><code>rcS.template</code></b>.
The file <code>apps/nshlib/rcS.template</code> contains the general form
of the <code>rcS</code> file; configured values are plugged into this
template file to produce the final <code>rcS</code> file.
</li>
</ol>
</p>
<p>
<b>NOTE</b>:
<code>apps/nshlib/rcS.template</code> generates the standard, default <code>nsh_romfsimg.h</code> file.
If <code>CONFIG_NSH_ARCHROMFS</code> is defined in the NuttX configuration file, then a custom, board-specific <code>nsh_romfsimg.h</code> file residing in <code>configs/&lt;board&gt;/include</code> will be used.
NOTE when the OS is configured, <code>include/arch/board</code> will be linked to <code>configs/&lt;board&gt;/include</code>.
</p>
<p>
All of the startup-behavior is contained in <code>rcS.template</code>. The
role of <code>mkromfsimg.sh</code> is to (1) apply the specific configuration
settings to <code>rcS.template</code> to create the final <code>rcS</code>, and (2) to
generate the header file <code>nsh_romfsimg.h</code> containg the ROMFS
file system image.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="commands"><h1>2.0 Commands</h1></a>
</td>
</tr>
</table>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdtest"><h2>2.1 Evaluate Expression (test)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
[ &lt;expression&gt; ]
test &lt;expression&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
These are two alternative forms of the same command. They support
evaluation of a boolean expression which sets <a href="#builtinvars"><code>$?</code></a>.
This command is used most frequently as the conditional command following the
<code>if</code> in the <a href="#conditional"><code>if-then[-else]-fi</code></a> construct.
</p>
<p><b>Expression Syntax:</b></p>
<ul>
<p>
expression = simple-expression | !expression | expression -o expression | expression -a expression
</p>
<p>
simple-expression = unary-expression | binary-expression
</p>
<p>
unary-expression = string-unary | file-unary
</p>
<p>
string-unary = -n string | -z string
</p>
<p>
file-unary = -b file | -c file | -d file | -e file | -f file | -r file | -s file | -w file
</p>
<p>
binary-expression = string-binary | numeric-binary
</p>
<p>
string-binary = string = string | string == string | string != string
</p>
<p>
numeric-binary = integer -eq integer | integer -ge integer | integer -gt integer | integer -le integer |
integer -lt integer | integer -ne integer
</p>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdcat"><h2>2.2 Concatenate Files (cat)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
cat <code>&lt;path&gt;</code> [<code>&lt;path&gt;</code> [<code>&lt;path&gt;</code> ...]]
</pre></ul>
<p>
<b>Synopsis</b>.
This command copies and concatentates all of the files at <code>&lt;path&gt;</code>
to the console (or to another file if the output is redirected).
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdcd"><h2>2.3 Change Current Working Directory (cd)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
cd [&lt;dir-path&gt;|-|~|..]
</pre></ul>
<p>
<b>Synopsis</b>.
Changes the current working directory (<code>PWD</code>). Also sets the
previous working directory environment variable (<code>OLDPWD</code>).
<p>
<p><b>Forms:</b></p>
<ul><table>
<tr>
<td><b><code>cd &lt;dir-path&gt;</code></b></td>
<td>sets the current working directory to <code>&lt;dir-path&gt;</code>.</td>
</tr>
<tr>
<td><b><code>cd -</code></b></td>
<td>sets the current working directory to the previous
working directory ($<a href="#environvars"><code>OLDPWD</code></a>).
Equivalent to <code><a href="#cmdcd">cd</a> $<a href="#environvars">OLDPWD</a></code>.</td>
</tr>
<tr>
<td><b><code>cd</code> or <b><code>cd ~</code></b></td>
<td>set the current working directory to the 'home'
directory. The <i>home</i> directory can be configured by setting
<code>CONFIG_LIB_HOMEDIR</code> in the configuration file. The default
<i>home</i> directory is <code>/</code>.</td>
</tr>
<tr>
<td><b><code>cd ..</code></td>
<td>sets the current working directory to the parent directory.</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdcp"><h2>2.4 Copy Files (cp)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
cp &lt;source-path&gt; &lt;dest-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Copy of the contents of the file at <code>&lt;source-path&gt;</code> to the location
in the filesystem indicated by <code>&lt;dest-path&gt;</code>.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmddate"><h2>2.5 Show or set the date and time (date)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
date [-s &quot;MMM DD HH:MM:SS YYYY&quot;]
</pre></ul>
<p>
<b>Synopsis</b>.
Show or set the current date and time.
This command is only supported if the platform supported RTC hardware (<code>CONFIG_RTC=y</code>).
</p>
<p>
Only one format is used both on display and when setting the date/time:
<code>MMM DD HH:MM:SS YYYY</code>. For example,
<ul><pre>
data -s &quot;Sep 1 11:30:00 2011&quot;
</pre></ul>
</p>
<p>
24-hour time is used.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmddd"><h2>2.6 Copy and Convert Files (dd)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
dd if=&lt;infile&gt; of=&lt;outfile&gt; [bs=&lt;sectsize&gt;] [count=&lt;sectors&gt;] [skip=&lt;sectors&gt;]
</pre></ul>
<p>
<b>Synopsis</b>.
Copy blocks from &lt;infile&gt; to &lt;outfile&gt;.
&lt;infile&gt; or &lt;outfile&gt; may be the path to a standard file, a character device, or a block device.
Examples follow:
</p>
<ol>
<li>
Read from character device, write to regular file.
This will create a new file of the specified size filled with zero.
<ul><pre>
nsh&gt; ls -l /dev
/dev:
crw-rw-rw- 0 zero
nsh&gt; dd if=/dev/zero of=/tmp/zeros bs=64 count=16
nsh&gt; ls -l /tmp
/tmp:
-rw-rw-rw- 1024 ZEROS
</pre></ul>
</li>
<li>
Read from character device, write to block device.
This will fill the entire block device with zeros.
</li>
<ul><pre>
nsh&gt; ls -l /dev
/dev:
brw-rw-rw- 0 ram0
crw-rw-rw- 0 zero
nsh&gt; dd if=/dev/zero of=/dev/ram0
</pre></ul>
</li>
<li>
Read from a block devic, write to a character device. This
will read the entire block device and dump the contents in
the bit bucket.
</li>
<ul><pre>
nsh&gt; ls -l /dev
/dev:
crw-rw-rw- 0 null
brw-rw-rw- 0 ram0
nsh&gt; dd if=/dev/ram0 of=/dev/null
</pre></ul>
</li>
</ol>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdecho"><h2>2.7 Echo Strings and Variables (echo)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
echo [&lt;string|$name&gt; [&lt;string|$name&gt;...]]
</pre></ul>
<p>
<b>Synopsis</b>.
Copy the sequence of strings and expanded environment variables to
console output (or to a file if the output is re-directed).
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdexec"><h2>2.8 Execute User Code (exec)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
exec &lt;hex-address&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Execute the user logic at address <code>&lt;hex-address&gt;</code>. NSH will pause
until the execution unless the user logic is executed in background
via <code><a href="#cmdexec">exec</a> &lt;hex-address&gt; &amp;</code>.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdexit"><h2>2.9 Exit NSH (exit)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
exit
</pre></ul>
<p>
<b>Synopsis</b>.
Exit NSH. Only useful for the serial front end if you have started some other tasks (perhaps
using the <code><a href="#cmdexec">exec</a></code> command) and you would like to have NSH out of the
way. For the telnet front-end, <code>exit</code> terminates the telenet session.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdfree"><h2>2.10 Show Memory Manager Status (free)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
free
</pre></ul>
<p>
<b>Synopsis</b>.
Show the current state of the memory allocator. For example,
</p>
<ul><pre>
nsh&gt; free
total used free largest
Mem: 4194288 1591552 2602736 2601584
nsh&gt;
</pre></ul>
<p><b>Where:</b></p>
<ul><table>
<tr>
<td><b><code>total</code></b></td>
<td>This is the total size of memory allocated for use by malloc in bytes.</td>
</tr>
<tr>
<td><b><code>used</code></b></td>
<td>This is the total size of memory occupied by chunks handed out by malloc.</td>
</tr>
<tr>
<td><b><code>free</code></b></td>
<td>This is the total size of memory occupied by free (not in use) chunks.</td>
</tr>
<tr>
<td><b><code>largest</code></b></td>
<td>Size of the largest free (not in use) chunk.</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdget"><h2>2.11 Get File Via TFTP (get)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
get [-b|-n] [-f &lt;local-path&gt;] -h &lt;ip-address&gt; &lt;remote-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Copy the file at <code>&lt;remote-address&gt;</code> from the host whose IP address is
identified by <code>&lt;ip-address&gt;</code>.
</p>
<p><b>Other options:</b></p>
<ul><table>
<tr>
<td><b><code>-f &lt;local-path&gt;</code></b></td>
<td>
The file will be saved relative to the current working directory
unless <code>&lt;local-path&gt;</code> is provided.
</td>
</tr>
<tr>
<td><b><code>-b|-n</code></b></td>
<td>
Selects either binary (&quot;octect&quot;) or test (&quot;netascii&quot;) transfer
mode. Default: text.
</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdhelp"><h2>2.12 Show Usage Command Usage (help)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
help
</pre></ul>
<p>
<b>Synopsis</b>.
Presents summary information about each command to console.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdifconfig"><h2>2.13 Show Network Configuration (ifconfig)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
ifconfig [nic_name [ip_address]]
</pre></ul>
<p>
<b>Synopsis</b>.
Two forms of the <code>ifconfig</code>command are supported:
</p>
<ol>
<li>
<p>
With one or no arguments, <code>ifconfig</code> will shows the
current configuration of the network and, perhaps, the status of ethernet
device:
</p>
<ul><pre>
ifconfig
ifconfig [nic_name]
</pre></ul>
<p>
As an example:
</p>
<ul><pre>
nsh&gt; ifconfig
eth0 HWaddr 00:18:11:80:10:06
IPaddr:10.0.0.2 DRaddr:10.0.0.1 Mask:255.255.255.0
</pre></ul>
<p>
If uIP statistics are enabled (<code>CONFIG_NET_STATISTICS</code>), then
this command will also show the detailed state of uIP.
</p>
</li>
<li>
<p>
If both the network interface name and an IP address are supplied as arguments,
then <code>ifconfig</code> will set the address of the ethernet device:
</p>
<ul><pre>
ifconfig nic_name ip_address
</pre><ul>
</li>
</ol>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdkill"><h2>2.14 Send a signal to a task (kill)</h2></a>
</td>
</tr>
</table>
<ul><pre>
kill -&lt;signal&gt; &lt;pid&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Send the &lt;signal&gt; to the task identified by &lt;pid&gt;.
</p>
<ul><pre>
nsh&gt; mkfifo /dev/fifo
nsh&gt; cat /dev/fifo &
cat [2:128]
nsh&gt; ps
PID PRI SCHD TYPE NP STATE NAME
0 0 FIFO TASK READY Idle Task()
1 128 FIFO TASK RUNNING init()
2 128 FIFO PTHREAD WAITSEM <pthread>(51ea50)
nsh&gt; kill -9 2
nsh: cat: open failed: 4
nsh&gt; ps
PID PRI SCHD TYPE NP STATE NAME
0 0 FIFO TASK READY Idle Task()
1 128 FIFO TASK RUNNING init()
nsh&gt;
</pre></ul>
<p><small>
<b>NOTE</b>:
NuttX does not support a FULL POSIX signalling system.
Standard signals like SIGCHLD, SIGINTR, SIGKILL, etc. do not exist in NuttX and sending those signal may not have the result that you expect.
Rather, NuttX supports only what are referred to as POSIX real-time signals.
These signals may be used to communicate with running tasks, may be use to waiting waiting tasks, etc.
But, as an example, <code>kill -9</code> (SIGKILL) will not terminate a task.
</p></small>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdlosetup"><h2>2.15 Setup/teardown the Loop Device (losetup)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax 1:</b></p>
<ul><pre>
losetup [-o <offset>] [-r] &lt;dev-path&gt; &lt;file-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Setup the loop device at &lt;dev-path&gt; to access the file at &lt;file-path&gt; as a block device.
In the following example a 256Kb file is created (<code>dd</code>) and <code>losetup</code> is
used to make the file accessible as a block device.
A FAT file system is created (<code>mkfatfs</code>) and mounted (<code>mount</code>).
Files can then be managed on the loop-mounted file.
<ul><pre>
nsh&gt; dd if=/dev/zero of=/tmp/image bs=512 count=512
nsh&gt; ls -l /tmp
/tmp:
-rw-rw-rw- 262144 IMAGE
nsh&gt; losetup /dev/loop0 /tmp/image
nsh&gt; ls -l /dev
/dev:
brw-rw-rw- 0 loop0
nsh&gt; mkfatfs /dev/loop0
nsh&gt; mount -t vfat /dev/loop0 /mnt/example
nsh&gt; ls -l /mnt
ls -l /mnt
/mnt:
drw-rw-rw- 0 example/
nsh&gt; echo &quot;This is a test&quot; &gt;/mnt/example/atest.txt
nsh&gt; ls -l /mnt/example
/mnt/example:
-rw-rw-rw- 16 ATEST.TXT
nsh&gt; cat /mnt/example/atest.txt
This is a test
nsh&gt;
</pre></ul>
</p>
<p><b>Command Syntax 2:</b></p>
<ul><pre>
losetup d &lt;dev-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Teardown the setup for the loop device at &lt;dev-path&gt;.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdls"><h2>2.16 List Directory Contents (ls)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
ls [-lRs] &lt;dir-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Show the contents of the directory at <code>&lt;dir-path&gt;</code>. NOTE:
<code>&lt;dir-path&gt;</code> must refer to a directory and no other filesystem
object.
</p>
<p><b>Options:</b></p>
<ul><table>
<tr>
<td><b><code>-R</code></b></td>
<td>Show the constents of specified directory and all of its
sub-directories.</td>
</tr>
<tr>
<td><b><code>-s</code></b></td>
<td>Show the size of the files along with the filenames in the
listing</td>
</tr>
<tr>
<td><b><code>-l</code></b></td>
<td>Show size and mode information along with the filenames
in the listing.</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdmbhw"><h2>2.17 Access Memory (mb, mh, and mw)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
mb &lt;hex-address&gt;[=&lt;hex-value&gt;][ &lt;hex-byte-count&gt;]
mh &lt;hex-address&gt;[=&lt;hex-value&gt;][ &lt;hex-byte-count&gt;]
mw &lt;hex-address&gt;[=&lt;hex-value&gt;][ &lt;hex-byte-count&gt;]
</pre></ul>
<p>
<b>Synopsis</b>.
Access memory using byte size access (mb), 16-bit accesses (mh),
or 32-bit access (mw). In each case,
</p>
<ul><table>
<tr>
<td><code>&lt;hex-address&gt;</code>.</td>
<td>Specifies the address to be accessed. The current
value at that address will always be read and displayed.
</tr>
<tr>
<td><code>&lt;hex-address&gt;=&lt;hex-value&gt;</code>.</td>
<td>Read the value, then write <code>&lt;hex-value&gt;</code>
to the location.
</tr>
<tr>
<td><code>&lt;hex-byte-count&gt;</code>.</td>
<td>Perform the mb, mh, or mw operation on a total
of <code>&lt;hex-byte-count&gt;</code> bytes, increment the <code>&lt;hex-address&gt;</code> appropriately
after each access
</tr>
</table></ul>
<p><b>Example:</b><p>
<ul><pre>
nsh&gt; mh 0 16
0 = 0x0c1e
2 = 0x0100
4 = 0x0c1e
6 = 0x0110
8 = 0x0c1e
a = 0x0120
c = 0x0c1e
e = 0x0130
10 = 0x0c1e
12 = 0x0140
14 = 0x0c1e
nsh&gt;
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdps"><h2>2.18 Show Current Tasks and Threads (ps)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
ps
</pre></ul>
<p>
<b>Synopsis</b>.
Show the currently active threads and tasks. For example,
</p>
<ul><pre>
nsh&gt; ps
PID PRI SCHD TYPE NP STATE NAME
0 0 FIFO TASK READY Idle Task()
1 128 RR TASK RUNNING init()
2 128 FIFO TASK WAITSEM nsh_telnetmain()
3 100 RR PTHREAD WAITSEM &lt;pthread&gt;(21)
nsh&gt;
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdmkdir"><h2>2.19 Create a Directory (mkdir)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
mkdir &lt;path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Create the directory at <code>&lt;path&gt;</code>.
All components of of <code>&lt;path&gt;</code> except the final directory name must exist on a mounted file
system; the final directory must not.
</p>
<p>
<b>Limited to Mounted File Systems</b>.
Recall that NuttX uses a <a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a> for its root file
system.
The <code>mkdir</code> command can only be used to create directories in volumes set up with the
<a href="#cmdmount"><code>mount</code></a> command; it cannot be used to create directories in the <i>pseudo</i> filesystem.
</p>
<p><b>Example:</b></p>
<ul><pre>
nsh> mkdir /mnt/fs/tmp
nsh> ls -l /mnt/fs
/mnt/fs:
drw-rw-rw- 0 TESTDIR/
drw-rw-rw- 0 TMP/
nsh>
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdmkfatfs"><h2>2.20 Create a FAT Filesystem (mkfatfs)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
mkfatfs &lt;path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Format a fat file system on the block device specified by <code>&lt;path&gt;</code>.
NSH provides this command to access the <a href="mkfatfs"><code>mkfatfs()</code></a> NuttX API.
This block device must reside in the NuttX <a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a> and
must have been created by some call to <code>register_blockdriver()</code> (see <code>include/nuttx/fs/fs.h</code>).
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdmkfifo"><h2>2.21 Create a FIFO (mkfifo)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
mkfifo &lt;path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Creates a FIFO character device anywhere in the pseudo file system, creating
whatever psuedo directories that may be needed to complete the <code>&lt;path&gt;</code>.
By convention, however, device drivers are place in the standard <code>/dev</code> directory.
After it is created, the FIFO device may be used as any other device driver.
NSH provides this command to access the <a href="NuttxUserGuide.html#mkfifo"><code>mkfifo()</code></a> NuttX API.
</p>
<p><b>Example</b></p>
<ul><pre>
nsh> ls -l /dev
/dev:
crw-rw-rw- 0 console
crw-rw-rw- 0 null
brw-rw-rw- 0 ram0
nsh> mkfifo /dev/fifo
nsh> ls -l /dev
ls -l /dev
/dev:
crw-rw-rw- 0 console
crw-rw-rw- 0 fifo
crw-rw-rw- 0 null
brw-rw-rw- 0 ram0
nsh>
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdmkrd"><h2>2.22 Create a RAMDISK (mkrd)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
mkrd [-m &lt;minor&gt;] [-s &lt;sector-size&gt;] &lt;nsectors&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Create a ramdisk consisting of <code>&lt;nsectors&gt;</code>, each of size
<code>&lt;sector-size&gt;</code> (or 512 bytes if <code>&lt;sector-size&gt;</code> is not specified.
The ramdisk will be registered as <code>/dev/ram&lt;n&gt;</code> (if <code>&lt;n&gt;</code> is not
specified, mkrd will attempt to register the ramdisk as <code>/dev/ram0</code>.
</p>
<p><b>Example</b></p>
<ul><pre>
nsh&gt; ls /dev
/dev:
console
null
ttyS0
ttyS1
nsh&gt; mkrd 1024
nsh&gt; ls /dev
/dev:
console
null
ram0
ttyS0
ttyS1
nsh&gt;
</pre></ul>
<p>
Once the ramdisk has been created, it may be formatted using
the <code>mkfatfs</code> command and mounted using the <code>mount</code> command.
</p>
<p><b>Example</b></p>
<ul><pre>
nsh&gt; mkrd 1024
nsh&gt; mkfatfs /dev/ram0
nsh&gt; mount -t vfat /dev/ram0 /tmp
nsh&gt; ls /tmp
/tmp:
nsh&gt;
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdmount"><h2>2.23 Mount a File System (mount)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
mount -t &lt;fstype&gt; &lt;block-device&gt; <code>&lt;dir-path&gt;</code>
</pre></ul>
<p>
<b>Synopsis</b>.
The 'm ount' command mounts a file system in the NuttX psuedo
filesystem. 'mount' performs a three way associating, binding:
</p>
<ol>
<li><b>File system.</b>
The '-t <code>&lt;fstype&gt;</code>' option identifies the type of
file system that has been formatted on the <code>&lt;block-device&gt;</code>.
As of this writing, <code>vfat</code> is the only supported value for <code>&lt;fstype&gt;</code>
</li>
<li><b>Block Device.</b>
The <code>&lt;block-device&gt;</code> argument is the full or relative
path to a block driver inode in the <a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a>.
By convention, this is a name under the <code>/dev</code> sub-directory.
This <code>&lt;block-device&gt;</code> must have been previously formatted with the same file system
type as specified by <code>&lt;fstype&gt;</code>
</li>
<li><b>Mount Point.</b>
The mount point, <code>&lt;dir-path&gt;</code>, is the location in the
<a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a> where the mounted volume will appear.
This mount point can only reside in the NuttX <a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a>.
By convention, this mount point is a subdirectory under <code>/mnt</code>.
The mount command will create whatever psuedo directories that may be needed to complete the
full path but the full path must not already exist.
</li>
</ol>
<p>
After the volume has been mounted in the NuttX
<a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a>,
it may be access in the same way as other objects in thefile system.
</p>
<p><b>Example</b></p>
<ul><pre>
nsh> ls -l /dev
/dev:
crw-rw-rw- 0 console
crw-rw-rw- 0 null
brw-rw-rw- 0 ram0
nsh> ls /mnt
nsh: ls: no such directory: /mnt
nsh> mount -t vfat /dev/ram0 /mnt/fs
nsh> ls -l /mnt/fs/testdir
/mnt/fs/testdir:
-rw-rw-rw- 15 TESTFILE.TXT
nsh> echo "This is a test" >/mnt/fs/testdir/example.txt
nsh> ls -l /mnt/fs/testdir
/mnt/fs/testdir:
-rw-rw-rw- 15 TESTFILE.TXT
-rw-rw-rw- 16 EXAMPLE.TXT
nsh> cat /mnt/fs/testdir/example.txt
This is a test
nsh>
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdping"><h2>2.24 Check Network Peer (ping)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
ping [-c &lt;count&gt;] [-i &lt;interval&gt;] &lt;ip-address&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Test the network communication with a remote peer. Example,
</p>
<ul><pre>
nsh&gt; ping 10.0.0.1
PING 10.0.0.1 56 bytes of data
56 bytes from 10.0.0.1: icmp_seq=1 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=2 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=3 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=4 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=5 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=6 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=7 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=8 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=9 time=0 ms
56 bytes from 10.0.0.1: icmp_seq=10 time=0 ms
10 packets transmitted, 10 received, 0% packet loss, time 10190 ms
nsh&gt;
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdput"><h2>2.25 Send File Via TFTP (put)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
put [-b|-n] [-f &lt;remote-path&gt;] -h &lt;ip-address&gt; &lt;local-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Copy the file at <code>&lt;local-address&gt;</code> to the host whose IP address is
identified by <code>&lt;ip-address&gt;</code>.
</p>
<p><b>Other options:</b></p>
<ul><table>
<tr>
<td><b><code>-f &lt;remote-path&gt;</code></b></td>
<td>
The file will be saved relative with the same name on the host
unless <code>&lt;remote-path&gt;</code> is provided.
</td>
</tr>
<tr>
<td><b><code>-b|-n</code></b></td>
<td>
Selects either binary (&quot;octect&quot;) or test (&quot;netascii&quot;) transfer
mode. Default: text.
</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdpwd"><h2>2.26 Show Current Working Directory (pwd)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
pwd
</pre></ul>
<p>
<b>Synopsis</b>.
Show the current working directory.
</p>
<ul><pre>
nsh&gt; cd /dev
nsh&gt; pwd
/dev
nsh&gt;
</pre></ul>
<p>Same as <code><a href="#cmdecho">echo</a> <a href="#environvars">$PWD</a></code>.</p>
<ul><pre>
nsh&gt; echo $PWD
/dev
nsh&gt;
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdrm"><h2>2.27 Remove a File (rm)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
rm &lt;file-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Remove the specified <code>&lt;file-path&gt;</code> name from the mounted file system.
Recall that NuttX uses a <a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a> for its root file
system.
The <code>rm</code> command can only be used to remove (unlink) files in volumes set up with the
<a href="#cmdmount"><code>mount</code></a> command;
it cannot be used to remove names in the <i>pseudo</i> filesystem.
</p>
<p><b>Example:</b></p>
<ul><pre>
nsh> ls /mnt/fs/testdir
/mnt/fs/testdir:
TESTFILE.TXT
EXAMPLE.TXT
nsh> rm /mnt/fs/testdir/example.txt
nsh> ls /mnt/fs/testdir
/mnt/fs/testdir:
TESTFILE.TXT
nsh>
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdrmdir"><h2>2.28 Remove a Directory (rmdir)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
rmdir &lt;dir-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Remove the specified <code>&lt;dir-path&gt;</code> directory from the mounted file system.
Recall that NuttX uses a <a href="NuttxUserGuide.html#FileSystemOverview"><i>pseudo</i> filesystem</a> for its root file
system.
The <code>rmdir</code> command can only be used to remove directories from volumes set up with the
<a href="#cmdmount"><code>mount</code></a> command;
it cannot be used to remove directories from the <i>pseudo</i> filesystem.
</p>
<p><b>Example:</b></p>
<ul><pre>
nsh> mkdir /mnt/fs/tmp
nsh> ls -l /mnt/fs
/mnt/fs:
drw-rw-rw- 0 TESTDIR/
drw-rw-rw- 0 TMP/
nsh> rmdir /mnt/fs/tmp
nsh> ls -l /mnt/fs
/mnt/fs:
drw-rw-rw- 0 TESTDIR/
nsh>
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdset"><h2>2.29 Set an Environment Variable (set)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
set &lt;name&gt; &lt;value&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Set the environment variable <code>&lt;name&gt;</code> to the string <code>&lt;value&gt;</code>.
For example,
</p>
<ul><pre>
nsh&gt; echo $foobar
nsh&gt; set foobar foovalue
nsh&gt; echo $foobar
foovalue
nsh&gt;
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdsh"><h2>2.30 Execute an NSH Script (sh)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
sh &lt;script-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Execute the sequence of NSH commands in the file referred
to by <code>&lt;script-path&gt;</code>.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdsleep"><h2>2.31 Wait for Seconds (sleep)</h2></a>
</td>
</tr>
</table>
<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>2.32 Unmount a File System (umount)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
umount &lt;dir-path&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Un-mount the file system at mount point <code>&lt;dir-path&gt;</code>.
The <code>umount</code> command can only be used to un-mount volumes previously mounted using
<a href="#cmdmount"><code>mount</code></a> command.
</p>
<p><b>Example:</b></p>
<ul><pre>
nsh> ls /mnt/fs
/mnt/fs:
TESTDIR/
nsh> umount /mnt/fs
nsh> ls /mnt/fs
/mnt/fs:
nsh: ls: no such directory: /mnt/fs
nsh>
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdunset"><h2>2.33 Unset an Environment Variable (unset)</h2></a>
</td>
</tr>
</table>
<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;</code>. Example:
</p>
<ul><pre>
nsh&gt; echo $foobar
foovalue
nsh&gt; unset foobar
nsh&gt; echo $foobar
nsh&gt;
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdusleep"><h2>2.34 Wait for Microseconds (usleep)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
usleep &lt;usec&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Pause execution (sleep) of <code>&lt;usec&gt;</code> microseconds.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdwget">2.35 Get File Via HTTP (wget)</a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
wget [-o &lt;local-path&gt;] &lt;url&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Use HTTP to copy the file at <code>&lt;url&gt;</code> to the current directory.
</p>
<p><b>Options:</b></p>
<ul><table>
<tr>
<td><b><code>-o &lt;local-path&gt;</code></b></td>
<td>
The file will be saved relative to the current working directory
and with the same name as on the HTTP server unless <code>&lt;local-path&gt;</code> is provided.
</td>
</tr>
</table></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="cmdxd"><h2>2.36 Hexadecimal dump (xd)</h2></a>
</td>
</tr>
</table>
<p><b>Command Syntax:</b></p>
<ul><pre>
xd &lt;hex-address&gt; &lt;byte-count&gt;
</pre></ul>
<p>
<b>Synopsis</b>.
Dump <code>&lt;byte-count&gt;</code> bytes of data from address <code>&lt;hex-address&gt;</code>.
</p>
<p><b>Example:</b></p>
<ul><pre>
nsh> xd 410e0 512
Hex dump:
0000: 00 00 00 00 9c 9d 03 00 00 00 00 01 11 01 10 06 ................
0010: 12 01 11 01 25 08 13 0b 03 08 1b 08 00 00 02 24 ....%..........$
...
01f0: 08 3a 0b 3b 0b 49 13 00 00 04 13 01 01 13 03 08 .:.;.I..........
nsh>
</pre></ul>
<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>
<p>
Note that in addition to general NuttX configuation settings, each NSH command can be
individually disabled via the settings in the rightmost column.
All of these settings make the configuration of NSH potentially complex but also allow it to
squeeze into very small memory footprints.
</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>
<th align="left">Can Be Disabled with</th>
</tr>
<tr>
<td><b><code>[</code></b></td>
<td>!<code>CONFIG_NSH_DISABLESCRIPT</code></td>
<td><code>CONFIG_NSH_DISABLE_TEST</code></td>
</tr>
<tr>
<td><b><code>cat</code></b></td>
<td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_CAT</code></td>
</tr>
<tr>
<td><b><code>cd</code></b></td>
<td>!<code>CONFIG_DISABLE_ENVIRON</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_CD</code></td>
</tr>
<tr>
<td><b><code>cp</code></b></td>
<td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_CP</code></td>
</tr>
<tr>
<td><b><code>date</code></b></td>
<td>!<code>CONFIG_DISABLE_CLOCK</code> &amp;&amp; <code>CONFIG_RTC</code></td>
<td><code>CONFIG_NSH_DISABLE_DATE</code></td>
</tr>
<tr>
<td><b><code>dd</code></b></td>
<td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_DD</code></td>
</tr>
<tr>
<td><b><code>echo</code></b></td>
<td><br></td>
<td><code>CONFIG_NSH_DISABLE_ECHO</code></td>
</tr>
<tr>
<td><b><code>exec</code></b></td>
<td><br></td>
<td><code>CONFIG_NSH_DISABLE_EXEC</code></td>
</tr>
<tr>
<td><b><code>exit</code></b></td>
<td><br></td>
<td><code>CONFIG_NSH_DISABLE_EXIT</code></td>
</tr>
<tr>
<td><b><code>free</code></b></td>
<td><br></td>
<td><code>CONFIG_NSH_DISABLE_FREE</code></td>
</tr>
<tr>
<td><b><code>get</code></b></td>
<td><code>CONFIG_NET</code> &amp;&amp; <code>CONFIG_NET_UDP</code> &amp;&amp;
<code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_NET_BUFSIZE</code> &gt;= 558<sup>1</sup></td>
<td><code>CONFIG_NSH_DISABLE_GET</code></td>
</tr>
<tr>
<td><b><code>help</code></b></td>
<td><br></td>
<td><code>CONFIG_NSH_DISABLE_HELP</code></td>
</tr>
<tr>
<td><b><code>ifconfig</code></b></td>
<td><code>CONFIG_NET</code></td>
<td><code>CONFIG_NSH_DISABLE_IFCONFIG</code></td>
</tr>
<tr>
<td><b><code>kill</code></b></td>
<td>!<code>CONFIG_DISABLE_SIGNALS</code></td>
<td><code>CONFIG_NSH_DISABLE_KILL</code></td>
</tr>
<tr>
<td><b><code>losetup</code></b></td>
<td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_LOSETUP</code></td>
</tr>
<tr>
<td><b><code>ls</code></b></td>
<td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_LS</code></td>
</tr>
<tr>
<td><b><code>mb,mh,mw</code></b></td>
<td><br></td>
<td>
<code>CONFIG_NSH_DISABLE_MB</code>,<br>
<code>CONFIG_NSH_DISABLE_MH</code>,<br>
<code>CONFIG_NSH_DISABLE_MW</code>
</td>
</tr>
<tr>
<td><b><code>mkdir</code></b></td>
<td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_FS_WRITABLE</code><sup>4</sup></td>
<td><code>CONFIG_NSH_DISABLE_MKDIR</code></td>
</tr>
<tr>
<td><b><code>mkfatfs</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>
<td><code>CONFIG_NSH_DISABLE_MKFATFS</code></td>
</tr>
<tr>
<td><b><code>mkfifo</code></b></td>
<td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_MKFIFO</code></td>
</tr>
<tr>
<td><b><code>mkrd</code></b></td>
<td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_FS_WRITABLE</code><sup>4</sup></td>
<td><code>CONFIG_NSH_DISABLE_MKRD</code></td>
</tr>
<tr>
<td><b><code>mount</code></b></td>
<td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> &amp;&amp; <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_FS_READABLE</code><sup>3</sup></td>
<td><code>CONFIG_NSH_DISABLE_MOUNT</code></td>
</tr>
<tr>
<td><b><code>ping</code></b></td>
<td><code>CONFIG_NET</code> &amp;&amp; <code>CONFIG_NET_ICMP</code> &amp;&amp;
<code>CONFIG_NET_ICMP_PING</code> &amp;&amp; !<code>CONFIG_DISABLE_CLOCK</code> &amp;&amp;
!<code>CONFIG_DISABLE_SIGNALS</code></td>
<td><code>CONFIG_NSH_DISABLE_PING</code></td>
</tr>
<tr>
<td><b><code>ps</code></b></td>
<td><br></td>
<td><code>CONFIG_NSH_DISABLE_PS</code></td>
</tr>
<tr>
<td><b><code>put</code></b></td>
<td><code>CONFIG_NET</code> &amp;&amp; <code>CONFIG_NET_UDP</code> &amp;&amp;
<code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_NET_BUFSIZE</code> &gt;= 558<sup>1,2</sup></td>
<td><code>CONFIG_NSH_DISABLE_PUT</code></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>
<td><code>CONFIG_NSH_DISABLE_PWD</code></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 &amp;&amp; <code>CONFIG_FS_WRITABLE</code><sup>4</sup></td>
<td><code>CONFIG_NSH_DISABLE_RM</code></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 &amp;&amp; <code>CONFIG_FS_WRITABLE</code><sup>4</sup></td>
<td><code>CONFIG_NSH_DISABLE_RMDIR</code></td>
</tr>
<tr>
<td><b><code>set</code></b></td>
<td>!<code>CONFIG_DISABLE_ENVIRON</code></td>
<td><code>CONFIG_NSH_DISABLE_SET</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_NSH_DISABLESCRIPT</code></td>
<td><code>CONFIG_NSH_DISABLE_SH</code></td>
</tr>
<tr>
<td><b><code>sleep</code></b></td>
<td>!<code>CONFIG_DISABLE_SIGNALS</code></td>
<td><code>CONFIG_NSH_DISABLE_SLEEP</code></td>
</tr>
<tr>
<td><b><code>test</code></b></td>
<td>!<code>CONFIG_NSH_DISABLESCRIPT</code></td>
<td><code>CONFIG_NSH_DISABLE_TEST</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_READABLE</code><sup>3</sup></td>
<td><code>CONFIG_NSH_DISABLE_UMOUNT</code></td>
</tr>
<tr>
<td><b><code>unset</code></b></td>
<td>!<code>CONFIG_DISABLE_ENVIRON</code></td>
<td><code>CONFIG_NSH_DISABLE_UNSET</code></td>
</tr>
<tr>
<td><b><code>usleep</code></b></td>
<td>!<code>CONFIG_DISABLE_SIGNALS</code></td>
<td><code>CONFIG_NSH_DISABLE_USLEEP</code></td>
</tr>
<tr>
<td><b><code>wget</code></b></td>
<td><code>CONFIG_NET</code> &amp;&amp; <code>CONFIG_NET_TCP</code> &amp;&amp;
<code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
<td><code>CONFIG_NSH_DISABLE_WGET</code></td>
</tr>
<tr>
<td><b><code>xd</code></b></td>
<td><br></td>
<td><code>CONFIG_NSH_DISABLE_XD</code></td>
</tr>
</table></center>
<p><sup>1</sup><small>
Because of hardware padding, the actual required packet size may be larger</small><br>
<sup>2</sup><small>
Special TFTP server start-up optionss will probably be required to permit
creation of files for the correct operation of the <code>put</code> command.</small><br>
<sup>3</sup><small>
<code>CONFIG_FS_READABLE</code> is not a user configuration but is set automatically
if any readable filesystem is selected. At present, this is either <code>CONFIG_FS_FAT</code>
or <code>CONFIG_FS_ROMFS</code>.</small><br>
<sup>4</sup><small>
<code>CONFIG_FS_WRITABLE</code> is not a user configuration but is set automatically
if any writable filesystem is selected. At present, this is only <code>CONFIG_FS_FAT</code>.</small><br>
</p>
<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 valign="top"><b><code>CONFIG_NSH_BUILTIN_APPS</code></b></td>
<td>
Support external registered, &quot;named&quot; applications that can be
executed from the NSH command line (see apps/README.txt for
more information).
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_FILEIOSIZE</code></b></td>
<td>
Size of a static I/O buffer used for file access (ignored if
there is no filesystem). Default is 1024.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_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 valign="top"><b><code>CONFIG_NSH_LINELEN</code></b></td>
<td>
The maximum length of one command line and of one output line.
Default: 80
</td>
</tr>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_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 valign="top"><b><code>CONFIG_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 valign="top"><b><code>CONFIG_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 valign="top"><b><code>CONFIG_NSH_MMCSDMINOR</code></b></td>
<td>
If the architecture supports an MMC/SD slot and if the NSH
architecture specific logic is present, this option will provide
the MMC/SD minor number, i.e., the MMC/SD block driver will
be registered as <code>/dev/mmcsd</code><i>N</i> where <i>N</i> is the minor number.
Default is zero.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_ROMFSETC</code></b></td>
<td>
Mount a ROMFS filesystem at <code>/etc</code> and provide a startup script
at <code>/etc/init.d/rcS</code>. The default startup script will mount
a FAT FS RAMDISK at <code>/tmp</code> but the logic is
<a href="#startupscript">easily extensible</a>.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_CONSOLE</code></b></td>
<td>
<p>
If <code>CONFIG_NSH_CONSOLE</code> is set to <i>y</i>, then a serial
console front-end is selected.
</p>
<p>
Normally, the serial console device is a UART and RS-232 interface.
However, if <code>CONFIG_USBDEV</code> is defined, then a USB serial device may, instead, be used if the one of the following are defined:
</p>
<ul>
<li>
<code>CONFIG_PL2303</code> and <code>CONFIG_PL2303_CONSOLE</code>.
Sets up the Prolifics PL2303 emulation as a console device at <code>/dev/console</code>.
</li>
<li>
<code>CONFIG_CDCACM</code> and <code>CONFIG_CDCACM_CONSOLE</code>.
Sets up the CDC/ACM serial device as a console device at <code>/dev/console</code>.
</li>
</ul>
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_CONDEV</code></b></td>
<td>
If <code>CONFIG_NSH_CONSOLE</code> is set to <i>y</i>, then <code>CONFIG_NSH_CONDEV</code>
may also be set to select the serial device used to support the NSH console.
This should be set to the quoted name of a readable/write-able character driver such as:
<code>CONFIG_NSH_CONDEV=&quot;/dev/ttyS1&quot;</code>.
This is useful, for example, to separate the NSH command line from the system console
when the system console is used to provide debug output.
Default: <code>stdin</code> and <code>stdout</code> (probably &quot;<code>/dev/console</code>&quot;)
<ul><small>
NOTE: When any other device other than <code>/dev/console</code> is used for a user interface,
(1) linefeeds (<code>\n</code>) will not be expanded to carriage return / linefeeds (<code>\r\n</code>).
You will need to configure your terminal program to account for this.
And (2) input is not automatically echoed so you will have to turn local echo on.
</small></ul>
</td>
<tr>
<td valign="top"><b><code>CONFIG_NSH_TELNET</code></b></td>
<td>
If <code>CONFIG_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>
<tr>
<td valign="top"><b><code>CONFIG_NSH_ARCHINIT</code></b></td>
<td>
Set <code>CONFIG_NSH_ARCHINIT</code> if your board provides architecture
specific initialization via the board-specific function <code>nsh_archinitialize()</code>.
This function will be called early in NSH initialization to allow board logic to
do such things as configure MMC/SD slots.
</td>
</tr>
</table></center>
<p>
If Telnet is selected for the NSH console, then we must configure
the resources used by the Telnet daemon and by the Telnet clients.
</p>
<center><table width="100%">
<tr bgcolor="#e4e4e4">
<th align="left" width="25%">Configuration</th>
<th align="left">Description</th>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_TELNETD_PORT</code></b></td>
<td>
The telnet daemon will listen on this TCP port number for connections. Default: 23
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_TELNETD_DAEMONPRIO</code></b></td>
<td>
Priority of the Telnet daemon.
Default: <code>SCHED_PRIORITY_DEFAULT</code>
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_TELNETD_DAEMONSTACKSIZE</code></b></td>
<td>
Stack size allocated for the
Telnet daemon. Default: 2048
</td>
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_TELNETD_CLIENTPRIO</code></b></td>
<td>
Priority of the Telnet client.
Default: <code>SCHED_PRIORITY_DEFAULT</code>
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_TELNETD_CLIENTSTACKSIZE</code></b></td>
<td>
Stack size allocated for the Telnet client. Default: 2048
</td>
</tr>
</table></center>
<p>
One or both of <code>CONFIG_NSH_CONSOLE</code> and <code>CONFIG_NSH_TELNET</code>
must be defined. If <code>CONFIG_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>
<tr>
<td valign="top"><b><code>CONFIG_NET=y</code></b></td>
<td>
Of course, networking must be enabled.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSOCKET_DESCRIPTORS</code></b></td>
<td>
And, of course, you must allocate some socket descriptors.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NET_TCP=y</code></b></td>
<td>
TCP/IP support is required for telnet (as well as various other TCP-related configuration settings).
</td>
</tr>
<td valign="top"><b><code>CONFIG_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 valign="top"><b><code>CONFIG_NSH_DHCPC</code></b></td>
<td>
Obtain the IP address via DHCP.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_IPADDR</code></b></td>
<td>
If <code>CONFIG_NSH_DHCPC</code> is NOT set, then the static IP
address must be provided.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_DRIPADDR</code></b></td>
<td>
Default router IP address
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_NETMASK</code></b></td>
<td>
Network mask
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_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></center>
<p>
If you use DHCPC, then some special configuration network options are
required. These include:
</p>
<center><table width="100%">
<tr bgcolor="#e4e4e4">
<th align="left" width="25%">Configuration</th>
<th align="left">Description</th>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NET=y</code></b></td>
<td>
Of course, networking must be enabled.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSOCKET_DESCRIPTORS</code></b></td>
<td>
And, of course, you must allocate some socket descriptors.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NET_UDP=y</code></b></td>
<td>
UDP support is required for DHCP (as well as various other UDP-related configuration settings).
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NET_BROADCAST=y</code></b></td>
<td>
UDP broadcast support is needed.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NET_BUFSIZE=650</code></b> (or larger)</td>
<td>
Per RFC2131 (p. 9), the DHCP client must be prepared to receive DHCP messages of up to
576 bytes (excluding Ethernet, IP, or UDP headers and FCS).
</td>
</tr>
</table></center>
<p>
If <code>CONFIG_NSH_ROMFSETC</code> is selected, then the following additional
configuration setting apply:
</p>
<center><table width="100%">
<tr bgcolor="#e4e4e4">
<th align="left" width="25%">Configuration</th>
<th align="left">Description</th>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_ARCHROMFS</code></b></td>
<td>
May be defined to specify an alternative ROMFS image that can be found at <code>configs/&lt;board&gt;/include/nsh_romfsimg.h</code>.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_ROMFSMOUNTPT</code></b></td>
<td>
The default mountpoint for the ROMFS volume is <code>&quot;/etc&quot;</code>, but that
can be changed with this setting. This must be a absolute path
beginning with '<code>/</code>' and enclosed in quotes.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_INITSCRIPT</code></b></td>
<td>
This is the relative path to the startup script within the mountpoint.
The default is <code>&quot;init.d/rcS&quot;</code>. This is a relative path and must not
start with '<code>/</code>' but must be enclosed in quotes.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_ROMFSDEVNO</code></b></td>
<td>
This is the minor number of the ROMFS block device. The default is
'<code>0</code>' corresponding to <code>/dev/ram0</code>.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_ROMFSSECTSIZE</code></b></td>
<td>
This is the sector size to use with the ROMFS volume. Since the
default volume is very small, this defaults to 64 but should be
increased if the ROMFS volume were to be become large. Any value
selected must be a power of 2.
</td>
</tr>
</table></center>
<p>
When the default <code>rcS</code> file used when <code>CONFIG_NSH_ROMFSETC</code> is
selected, it will mount a FAT FS under <code>/tmp</code>. The following selections
describe that FAT FS.
</p>
<center><table width="100%">
<tr bgcolor="#e4e4e4">
<th align="left" width="25%">Configuration</th>
<th align="left">Description</th>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_FATDEVNO</code></b></td>
<td>
This is the minor number of the FAT FS block device. The default is
'<code>1</code>' corresponding to <code>/dev/ram1</code>.
</td>
</tr>
<tr>
<td valign="top"><b><code>CONFIG_NSH_FATSECTSIZE</code></b></td>
<td>
This is the sector size use with the FAT FS. Default is 512.
</td>
</tr>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="index"><h1>Index</h1></a>
</td>
</tr>
</table>
<table width="100%">
<tr><td width="50%">
<ul>
<li><a href="#builtinvars"><code>$?</code></a></li>
<li><a href="#cmdtest"><code>[</code></a></li>
<li><a href="#cmdoverview">Background commands</a></li>
<li><a href="#cmdoverview">Background command priority</a></li>
<li><a href="#builtinvars">Built-in variables</a></li>
<li><a href="#cmdcat"><code>cat</code></a></li>
<li><a href="#cmdcd"><code>cd</code></a></li>
<li><a href="#commands">Command summaries</a></li>
<li><a href="#conditional">Conditional command execution</a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_CONSOLE</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_DHCPC</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_DISABLEBG</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_DISABLESCRIPT</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_DRIPADDR</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_FATDEVNO</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_FATMOUNTPT</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_FATNSECTORS</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_FATSECTSIZE</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_FILEIOSIZE</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_INITSCRIPT</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_IOBUFFER_SIZE</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_IPADDR</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_LINELEN</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_NESTDEPTH</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_NETMASK</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_NOMAC</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_ROMFSDEVNO</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_ROMFSETC</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_ARCHROMFS</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_ROMFSMOUNTPT</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_ROMFSSECTSIZE</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_STRERROR</code></a></li>
<li><a href="#nshconfiguration"><code>CONFIG_NSH_TELNET</code></a></li>
<li><a href="#configuration">Configuration settings</a></li>
<li><a href="#cmddependencies">Configuration settings, command dependencies</a></li>
<li><a href="#nshconfiguration">Configuration settings, NSH-specific</a></li>
<li><a href="#cmdcp"><code>cp</code></a></li>
<li><a href="#currentwd">Current working directory</a></li>
<li><a href="#cmddate"><code>date</code></a></li>
<li><a href="#cmddd"><code>dd</code></a></li>
<li><a href="#cmdecho"><code>echo</code></a></li>
<li><a href="#environvars">Environment Variables</a></li>
<li><a href="#startupscript"><code>/etc/init.d/rcS</code></a>
</ul></td>
<td></ul>
<li><a href="#cmdexec"><code>exec</code></a></li>
<li><a href="#cmdexit"><code>exit</code></a></li>
<li><a href="#cmdfree"><code>free</code></a></li>
<li><a href="#cmdget"><code>get</code></a></li>
<li><a href="#frontend">Greeting</a></li>
<li><a href="#cmdhelp"><code>help</code></a></li>
<li><a href="#conditional"><code>if-then[-else]-fi</code></a></li>
<li><a href="#cmdifconfig"><code>ifconfig</code></a></li>
<li><a href="#cmdkill"><code>kill</code></a></li>
<li><a href="#cmdlosetup"><code>losetup</code></a></li>
<li><a href="#cmdls">ls</code></a></li>
<li><a href="#cmdmbhw"><code>mb</code></a></li>
<li><a href="#cmdmbhw"><code>mh</code></a></li>
<li><a href="#cmdmbhw"><code>mw</code></a></li>
<li><a href="#cmdmkdir"><code>mkdir</code></a></li>
<li><a href="#cmdmkfatfs"><code>mkfatfs</code></a></li>
<li><a href="#cmdmkfifo"><code>mkfifo</code></a></li>
<li><a href="#cmdmkrd"><code>mkrd</code></a></li>
<li><a href="#cmdmount"><code>mount</code></a></li>
<li><a href="#cmdoverview"><code>nice</code></a></li>
<li><a href="#environvars"><code>OLDPWD</code></a></li>
<li><a href="#overview">Overview</a></li>
<li><a href="#cmdping"><code>ping</code></a></li>
<li><a href="#frontend">Prompt</a></li>
<li><a href="#cmdps"><code>ps</code></a></li>
<li><a href="#cmdput"><code>put</code></a></li>
<li><a href="#cmdpwd"><code>pwd</code></a></li>
<li><a href="#environvars"><code>PWD</code></a></li>
<li><a href="#cmdoverview">Re-directed commands</a></li>
<li><a href="#cmdrm"><code>rm</code></a></li>
<li><a href="#cmdrmdir"><code>rmdir</code></a></li>
<li><a href="#cmdset"><code>set</code></a></li>
<li><a href="#cmdsh"><code>sh</code></a></li>
<li><a href="#cmdoverview">Simple commands</a></li>
<li><a href="#cmdsleep"><code>sleep</code></a></li>
<li><a href="#startupscript">start-up script</a>
<li><a href="#cmdtest"><code>test</code></a></li>
<li><a href="#cmdunmount"><code>umount</code></a></li>
<li><a href="#cmdunset"><code>unset</code></a></li>
<li><a href="#cmdusleep"><code>usleep</code></a></li>
<li><a href="#cmdwget"><code>wget</code></a></li>
<li><a href="#cmdxd"><code>xd</code></a></li>
</ul></td>
</tr></table>
</body>
</html>