模式内的Grep模式

Question

cat sudo.txt |tr -d "[:blank:]"|grep '=.*[ALLroot].*/usr/bin/vim'

我要跟踪以下内容：

=(root)NOPASSWD:/usr/bin/vim
=(ALL)NOPASSWD:/usr/bin/vim
=NOPASSWD:/usr/bin/vim

但不是：

=(user)NOPASSWD:/usr/bin/find

Answer 1

给出数据，

grep -E '\bNOPASSWD:/usr/bin/vim\b' sudo.txt

如果选择还不够，请显示示例并解释缺少的要求。

Answer 2

[ALLroot]匹配A或L或r或o或t。请改用(ALL|root)

给出：

cat sudo.txt
=(root)NOPASSWD:/usr/bin/vim
=(ALL)NOPASSWD:/usr/bin/vim
=NOPASSWD:/usr/bin/vim
=(user)NOPASSWD:/usr/bin/find

---

grep -E '=(\((root|ALL)\))?.*/usr/bin/vim' sudo.txt
=(root)NOPASSWD:/usr/bin/vim
=(ALL)NOPASSWD:/usr/bin/vim
=NOPASSWD:/usr/bin/vim

说明：

选项-E：扩展模式

=                   # equal sign
(                   # start group
  \(                # opening parenthesis
    (root|ALL)      # root OR ALL
  \)                # closing parenthesis
)?                  # end group, optional
.*                  # 0 or more any character
/usr/bin/vim        # literally