a test.c</PRE>
<P>
 and the command:</P>
<PRE>var a abc${outfile}tmp</PRE>
<P>
is equivalent to the command:</P>
<PRE>var a abctesttmp</PRE>
<P>
Variable substitution does not occur in arguments that are enclosed in braces: the dollar sign and variable name are passed through to the argument verbatim.</P>
<P>
The dollar sign abbreviation is simply a shorthand form. <CODE>
$a</CODE>
 is completely equivalent to<CODE>
 [var a]</CODE>
; it is provided as a convenience to reduce typing.</P>


<H2 CLASS="Heading