正则表达式方括号

Question

我可以使用 Bash 来匹配一组字符

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

但是，如果我想要一个右方括号 ] 包含在集合中，它会失败

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

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

Answer 1

来自手册页 regex(7):

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

测试:

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