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backward-compatible. It's preferable to use <TT>true</TT>,
<TT>false</TT>, and <TT>nil</TT>. </P><A
name=IXT-3-127236></A><A name=IXT-3-127237></A><A
name=IXT-3-127238></A><A name=IXT-3-127239></A><A
name=IXT-3-127240></A><A name=IXT-3-127241></A><A
name=IXT-3-127242></A><A name=IXT-3-127243></A><A
name=IXT-3-127244></A><A name=IXT-3-127245></A><A
name=IXT-3-127246></A><A name=IXT-3-127247></A><A
name=IXT-3-127248></A><A name=IXT-3-127249></A><A
name=IXT-3-127250></A><A name=IXT-3-127251></A><A
name=IXT-3-127252></A><A name=IXT-3-127253></A>
<DL class=docList><A name=IXT-3-127236></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>TRUE</SPAN></SPAN></SPAN>
<DD>
<P class=docList>Synonym for <TT>true</TT>.</P><A
name=IXT-3-127237></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>FALSE</SPAN></SPAN></SPAN>
<DD>
<P class=docList>Synonym for <TT>false</TT>.</P>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>NIL</SPAN></SPAN></SPAN>
<DD>
<P class=docList>Synonym for <TT>nil</TT>.</P><A
name=IXT-3-127238></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>ARGF</SPAN></SPAN></SPAN>
<DD>
<P class=docList>An object providing access to virtual
concatenation of files passed as command-line arguments or
standard input if there are no command-line arguments. A
synonym for <TT>$<</TT>. </P><A name=IXT-3-127239></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>ARGV</SPAN></SPAN></SPAN>
<DD>
<P class=docList>An array containing the command-line
arguments passed to the program. A synonym for <TT>$*</TT>.
</P><A name=IXT-3-127240></A><A name=IXT-3-127241></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>DATA</SPAN></SPAN></SPAN>
<DD>
<P class=docList>An input stream for reading the lines of
code following the __<TT>END</TT>__ directive. Not defined
if __<TT>END</TT>__ isn't present in code. </P><A
name=IXT-3-127242></A><A name=IXT-3-127243></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>ENV</SPAN></SPAN></SPAN>
<DD>
<P class=docList>A hash-like object containing the program's
environment variables. <TT>ENV</TT> can be handled as a
hash. </P><A name=IXT-3-127244></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>RUBY_PLATFORM</SPAN></SPAN></SPAN>
<DD>
<P class=docList>A string indicating the platform of the
Ruby interpreter, e.g., <TT>i686-linux</TT>. </P><A
name=IXT-3-127245></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>RUBY_RELEASE_DATE</SPAN></SPAN></SPAN>
<DD>
<P class=docList>A string indicating the release date of the
Ruby interpreter, e.g., <TT>2001-09-19</TT>. </P><A
name=IXT-3-127246></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>RUBY_VERSION</SPAN></SPAN></SPAN>
<DD>
<P class=docList>A string indicating the version of the Ruby
interpreter, e.g., <TT>1.6.5</TT>. </P><A
name=IXT-3-127247></A><A name=IXT-3-127248></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>STDERR</SPAN></SPAN></SPAN>
<DD>
<P class=docList>Standard error output stream. Default value
of <TT>$stderr</TT>. </P><A name=IXT-3-127249></A><A
name=IXT-3-127250></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>STDIN</SPAN></SPAN></SPAN>
<DD>
<P class=docList>Standard input stream. Default value of
<TT>$stdin</TT>.</P><A name=IXT-3-127251></A><A
name=IXT-3-127252></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>STDOUT</SPAN></SPAN></SPAN>
<DD>
<P class=docList>Standard output stream. Default value of
<TT>$stdout</TT>.</P><A name=IXT-3-127253></A>
<DT><SPAN class=docPubcolor><SPAN class=docPubcolor><SPAN
class=docMonofont>TOPLEVEL_BINDING</SPAN></SPAN></SPAN>
<DD>
<P class=docList>A <TT>Binding</TT> object at Ruby's top
level.</P></DD></DL><A
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