grep -E 'stra|strb' // 查找包含stra或strb的行 grep ^str // 查找以str开头的行 grep -i str // 忽略大小写 grep -rl str /root // 在/root下查找包含str的文件，并只列出文件名 -r表示递归目录匹配 grep -n str // 显示行号 grep --color str // 染成红色或加重 grep -e // 将两个表达式连在一起，比如：grep -e ^str1 -e str2$ ？？？？
grep -B12 str // 显示str所在行及其前12行
grep -A23 str // 显示str所在行及其后23行
grep -C34 str // 显示str所在行及其前后34行
附：
[abc] A single character: a, b or c
[^abc] Any single character but a, b, or c
[a-z] Any single character in the range a-z
[a-zA-Z] Any single character in the range a-z or A-Z
^ Start of line
$ End of line
\A Start of string
\z End of string
. Any single character
\s Any whitespace character
\S Any non-whitespace character
\d Any digit
\D Any non-digit
\w Any word character (letter, number, underscore)
\W Any non-word character
\b Any word boundary character
(...) Capture everything enclosed
(a|b) a or b
a? Zero or one of a
a* Zero or more of a
a+ One or more of a
a{3} Exactly 3 of a
a{3,} 3 or more of a
a{3,6} Between 3 and 6 of a
options: i case insensitive m make dot match newlines x ignore whitespace in regex o perform #{...} substitutions only once
刚才从同事那里得到了一张神图，是vi的，顺便贴在这吧