Perl语言入门：第七章习题：输出文件中包含一个大写字母的所有行，不输出一行的内容全是大写的

文件内容：

bash-2.03$ cat file_4_ex_ch7.txt
anonymous attribute demolition grammar rules indices refernces lignA
Align,

ligning.
.
AABB

代码：

80 print "\n----------------------------------exercise_ch7_4--------------------------\n";
     81 while(<>){
     82     if(/[A-Z][a-z]+/){
     83         print $_."\n" ;
     84     }
     85     if(/[a-z][A-Z]/){
     86         print $_."\n" ;
     87     }
     88 }
     89 print "\n----------------------------------exercise_ch7_4--------------------------\n";

输出：

----------------------------------exercise_ch7_4--------------------------
anonymous attribute demolition grammar rules indices refernces lignA

Align,

----------------------------------exercise_ch7_4--------------------------