1、You may receive error messages about strcasecmp as well as about strlen being undeclared.
2、没有相关系统调用的库函数的一个示例是string . h中声明的strlen函数。
3、An example of a library function that does not have an associated system call is the strlen function declared in string.h.
4、接下来的函数确定每个赋值项的lvalue的长度,这通过将strlen函数映*到已过滤的函数的副本上来实现。