shell攻略-让文本飞

[hadoop@localhost 桌面]$ echo this is a line. |egrep -o"[a-z]+\."
line.




查找指定文本所在行
[hadoop@localhost 桌面]$ echo -e "1 2 3 4\nhello\n5 6" |egrep "[0-9]"
1 2 3 4
5 6


计算行数
[hadoop@localhost 桌面]$ echo -e "1 2 3 4\nhello\n5 6" |egrep -c "[0-9]"
2




[hadoop@localhost 桌面]$ echo -e "1 2 3 4\nhello\n5 6" |egrep -o "[0-9]"
1
2
3
4
5
6


统计字符个数
[hadoop@localhost 桌面]$ echo -e "1 2 3 4\nhello\n5 6" |egrep -o "[0-9]"| wc -l
6


搜索当前目录下某些文本位于哪些文件中
[hadoop@localhost 桌面]$ grep "Open Source" . -R -n
./regular_express.txt:1:"Open Source" is a good mechanism to develop programs.
[hadoop@localhost 桌面]$ cat regular_express.txt
"Open Source" is a good mechanism to develop programs.
apple is my favorite food.
Football game is not use feet only.
this dress doesn't fit me.
However, this dress is about $ 3183 dollars.
GNU is free air not free beer.
Her hair is very beauty.
I can't finish the test.
[e-mail]
http://www.google.com




[hadoop@localhost 桌面]$ egrep -o '[A-Za-z0-9.]+@[A-Za-z0-9.]+\.[A-Za-z]{2,4}' regular_express.txt
[e-mail]
[hadoop@localhost 桌面]$ egrep -o 'http://[A-Za-z0-9.]+\.[A-Za-z]{2,4}' regular_express.txt
http://www.google.com




[hadoop@localhost 桌面]$ echo this this this this is a book this |sed 's/this/That/2g'
this That That That is a book That
[hadoop@localhost 桌面]$ echo this this this this is a book this |sed 's/this/That/1g'
That That That That is a book That
[hadoop@localhost 桌面]$ echo this this this this is a book this |sed 's/this/That/2g'
this That That That is a book That
[hadoop@localhost 桌面]$ echo this this this this is a book this |sed 's/this/That/3g'
this this That That is a book That
[hadoop@localhost 桌面]$ echo this this this this is a book this |sed 's/this/That/4g'
this this this That is a book That
[hadoop@localhost 桌面]$ echo this this this this is a book this |sed 's/this/That/5g'
this this this this is a book That