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关于嵌入式编程的tcl语法的资料

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<pre>
<code style="font-family: Courier New, Courier, monospace; font-size: 12">
...
#
# parse command line switches
set Optimize 0
set Verbose	0

foreach Arg $argv {
	switch -glob -- $Arg {
		-o* {set Optimize 1}
		-v* {set Verbose 1}
		default {
			error "Unknown $Arg"
		}
	}
}

set LineCount 0
while {[gets stdin Line] &gt;= 0} {
	# to confuse Vanna White...
	Remove_Vowels $Line \
		$Optimize $Verbose
	incr LineCount
}
return LineCount
...

			</code>
</pre>
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<td width="90%"><font size="4" face="Verdana, Arial, Helvetica"><b>Tcl 中的循环和分支</b></font></td><td width="200" align="right"><font size="1" face="Verdana, Arial, Helvetica"><nobr>   第 5 页（共15 页）</nobr></font></td>
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<font size="2" face="Verdana, Arial, Helvetica">
<p>Tcl 中的循环命令是 <i>while</i>、<i>for</i> 和 <i>foreach</i>。条件（转移）命令是
<i>if/then/else/elsif</i> 和 <i>switch</i>。上述命令的限定语句是 <i>break</i>、<i>continue</i>、<i>return</i>
和 <i>error</i>。最后，<i>catch</i> 命令提供了错误处理能力。</p>
<p>
						
<i>if/then/else/elsif</i> 已在前面几屏中演示过。在正式语法中会用到 <i>then</i>，但通常会省略掉它。</p>
<p>在左边这个示例中，<i>foreach</i> 结构给 <i>switch</i> 命令提供命令行自变量。当处理自变量时（注意：不正确的输入会终止脚本，因为还没有实现处理错误的 <i>catch</i>），<i>while</i> 循环通过为每一行调用过程并同时对行计数器<i>加</i> 1 来处理输入。代码段结束时，<i>返回</i>处理的行数。</p>
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