检查每个读取的字符是否为换页符；若是，则增加页计数器。
Check each char read to see whether it is a form feed; if so, increment the page counter.
用于换页定界的页的逻辑大体上相同，只是稍稍简单一些，因为不需要行计数器：使用getc库函数逐个读取字符。
The logic used for form-feed-delimited pages is roughly the same, but slightly simpler, as there is no need for a line counter: Read char by char using the getc library function.
不一定指那些在屏幕上可见的文本，还包括如换页换行符、段分隔符和图形字符等等。
Not always visible as text on the screen. For instance, includes page and line breaks, paragraph delimiters and picture characters.
应用推荐