以文本文件形式输入源程序，并对源程序从左到右进行扫描，把构成源程序的字符串拼接成为单词串；并把其转换成属性字输出到文件中。 -A text file input source, and the source code to scan from left to right, to constitute a source word string string splicing and to convert it into a property of word output to a file