aaaaaaa aaaa bbbbbb ccccccccccc dddd aa aaaaaaa bbbbbbbb cccccccccc ddddddddddddd eeeeeee aaaaaaaaaaaa bbbbbbbbbbb cccccccccccccccccccc aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aa aaaaaaaaaaaaaaaaaaaaaaaaaaaa bbbbbbbbbb aaaaaaaaa ccccccccc bbbbbbbbbbbbb ddddddddddddddddd
aaaaaaaaa ccccccccc bbbbbbbbbbbbb ddddddddddddddddd
具体逻辑参考代码注释
文件读取:http://www.cnblogs.com/iloveyoucc/archive/2012/07/10/2585529.html 关系运算符:http://www.runoob.com/linux/linux-shell-basic-operators.html shell变量里的字符替换:http://blog.csdn.net/augusdi/article/details/41010041
1.测试当前文件
2.更改最大字符串行数