linux grep

1.grep

文本：

hello msb
hello angelababy
hello dilireba
iiii250 wyf
hello zhangxinyi
11 hel mhellosbjy lo
h2341123i bj
iiii521 fanbingbing
111 hello 222
wo ai bj tam
hellor1chie
hihelloahello
helloahiahelloahi

1.查找包含hello的行

grep "hello"  test.txt

2.查找包含数字的行

grep "[0-9]"  test.txt

3.查找包含了2或5的行

grep "[25]" test.txt

4.查找包含三位数字的行

grep -E "[0-9]{3}" test.txt

5.查找只包含hello这个单词的行

grep "\<hello\>"  test.txt

6.查找包含3位数的行

grep -E "(^[0-9]|[^0-9][0-9])[0-9]([0-9][^0-9]|[0-9]$)" test.txt

7.查找hello单词为首的行

grep "^\<hello\>" test.txt

8.查找出现2~3次l的行

grep -E "[l]{2,3}" test.txt

9.查找出hi hello hi hello的行

grep "hi.*hello.*hi.*hello.*" test.txt
grep -E "(hi.*)(hello.*).*\1.*\2" test.txt