摘要：
正则表达式A regular expression is a pattern template you define that a Linux utility(sed,gawk等) uses to filter text.正则表达式由正则表达式引擎来实现(regular expression engine)。In the Linux world, there are two popular regular expression engines:■ The POSIX Basic Regular Expression (BRE) engine■ The POSIX Extended Regula 阅读全文
