cygwin bash中正则表达式使用方法

教科书告诉我，用bash进行正则表达式比较，用如下方式：

 

if [[ "$1" =~ '^[[:space:]]*#' ]]

 

然而将同样语句移植到cygwin中会发生死活认不出的情况。研究了一下，将语句作如下修改：

 

if [[ $1 =~ ^[[:space:]]*# ]]

 

即可。

 

原因如下：

In bash 3.2, the [[ ]] quoting rules changed slightly.  Since [[ already
introduces special quoting rules, single quotes are not required; the
regex is already protected by the shell from globbing.