类似：
http://img.qq.com/news/2010-9/201091922363125079_C.jpg
替换为
http://img.qq.com/news/2010-9/201091922363125079_c.jpg
http://img.qq.com/news/2010-9/201091922361111071_C.jpg
替换为
http://img.qq.com/news/2010-9/201091922361111071_c.jpg
http://img.qq.com/news/2010-9/201091922293193192_A.jpg
替换为
http://img.qq.com/news/2010-9/201091922293193192_a.jpg
http://img.qq.com/news/2010-9/201091922293103194_A.jpg
替换为
http://img.qq.com/news/2010-9/201091922293103194_a.jpg
http://img.qq.com/news/2010-9/201091919175936284_B.jpg
替换为
http://img.qq.com/news/2010-9/201091919175936284_b.jpg
http://img.qq.com/news/2010-9/201091923175936285_B.jpg
替换为
http://img.qq.com/news/2010-9/201091923175936285_b.jpg
http://img.qq.com/news/2010-9/201091922363125079_C.jpg
替换为
http://img.qq.com/news/2010-9/201091922363125079_c.jpg
http://img.qq.com/news/2010-9/201091922361111071_C.jpg
替换为
http://img.qq.com/news/2010-9/201091922361111071_c.jpg
http://img.qq.com/news/2010-9/201091922293193192_A.jpg
替换为
http://img.qq.com/news/2010-9/201091922293193192_a.jpg
http://img.qq.com/news/2010-9/201091922293103194_A.jpg
替换为
http://img.qq.com/news/2010-9/201091922293103194_a.jpg
http://img.qq.com/news/2010-9/201091919175936284_B.jpg
替换为
http://img.qq.com/news/2010-9/201091919175936284_b.jpg
http://img.qq.com/news/2010-9/201091923175936285_B.jpg
替换为
http://img.qq.com/news/2010-9/201091923175936285_b.jpg
本文转自 liang3391 51CTO博客，原文链接:http://blog.51cto.com/liang3391/623584
![Shell的正则表达式入门、常规匹配、特殊字符：^、$、.、*、字符区间（中括号）：[ ]、特殊字符：\、匹配手机号](https://ucc.alicdn.com/images/user-upload-01/5d0d6755d97a4485b942e13476146b02.png?x-oss-process=image/resize,h_160,m_lfit)
