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<p>
<a href="index.html">execline</a><br />
<a href="http://skarnet.org/software/">Software</a><br />
<a href="http://skarnet.org/">skarnet.org</a>
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<h1> The <tt>dollarat</tt> program </h1>

<p>
<tt>dollarat</tt> prints the positional parameters of an execline script.
</p>

<h2> Interface </h2>

<pre>
     dollarat [ -n ] [ -0 | -d <em>delimchar</em> ]
</pre>

<ul>
 <li> <tt>dollarat</tt> reads the number <em>n</em> of "positional
parameters" in the <tt>#</tt> environment variable. If that variable
is not set or does not contain a valid <em>n</em>, <tt>dollarat</tt>
exits 100. </li>
 <li> <tt>dollarat</tt> prints the value of the <tt>1</tt> environment
variable, then <em>delimchar</em>, then the value of the <tt>2</tt>
environment variable... and so on until <tt><em>n</em></tt>. If one of
these variables is not set, <tt>dollarat</tt> exits 100. </li>
 <li> If everything runs OK, <tt>dollarat</tt> exits 0. This makes it
one of the rare "exiting" execline commands. </li>
</ul>

<h2> Options </h2>

<ul>
 <li> <tt>-n</tt>&nbsp;: <em>chomp</em>. Do not print the last
<em>delimchar</em>. </li>
 <li> <tt>-d</tt>&nbsp;<em>delimchar</em>&nbsp;: use the character
<em>delimchar</em> as separator between the arguments. Default: <tt>\n</tt>.
If <em>delimchar</em> has more than one character, only the first one is
used. If <em>delimchar</em> is the empty string, then <tt>dollarat</tt>
will output the positional parameters as a
<a href="el_transform.html#netstrings">sequence of netstrings</a> (and the
<tt>-n</tt> option will be ignored). </li>
 <li> <tt>-0</tt>&nbsp;: use the null character as separator. Any <tt>-d</tt>
argument will be ignored. Warning: this option should only be used to feed
data to programs that know how to handle null-separated lists. </li>
</ul>

<h2> Notes </h2>

<ul>
 <li> You can use <tt>dollarat&nbsp;-d&nbsp;""</tt> along with the
<a href="forbacktickx.html">forbacktickx</a> command to reliably loop
over the positional parameters:
<pre>
 #!/command/execlineb
 forbacktickx -d "" ARG { dollarat -d "" }
 dosomething $ARG
</pre>

 will call <tt>dosomething</tt> in turn on each argument to the script.
That will work even if those arguments contain spaces, newlines,
or other fancy characters. </li>

 <li> Alternatively, instead of encoding data into a netstring, you can
use a null-separated list, which will work the same way:
<pre>
 #!/command/execlineb
 forbacktickx -0 ARG { dollarat -0 }
 dosomething $ARG
</pre> </li>
</ul>

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