regex - 正则表达式方右括号

Question

我可以使用 Bash 来匹配一组字符

$ [[ a =~ [abc] ]]; echo $?
0

]但是，如果我想在集合中包含一个右方括号，它会失败

$ [[ a =~ [abc\]] ]]; echo $?
1

$ [[ a =~ [abc\\]] ]]; echo $?
1

Answer 1

从手册页regex(7)：

To include a literal ']' in the list, make it the first character (fol-
lowing a possible '^').  

测试：

$ [[ "]" =~ []abc] ]]; echo $?
0