Linux Learning notes: SED

SED command

Row-based operations to replace, delete, add, and stdin data

The parameters are as follows

-N Quiet mode. By default, sed outputs all content, including modified and unmodified content. Use-n will only output the modified line of content.

-R supports extended regular expressions

-I directly modifies the file and does not output content

Parameter-I operates directly on the file and does not output anything.

Sed-i ' $aEND line ' regular_express.txt

$ is the last line meaning, used to specify the range. A is the insert action. END Line is a row of content

[email protected] ~]# cat Regular_express.txt

"Open Source" is a good mechanism to develop programs.

Apple is my favorite food.

......

Gnu

END Line

Line Range

N1,n2 optional, specifies that SED moves only from N1 lines to N2

Action

A new, add a line under each line in the range, example

[Email protected] ~]# cat-n regular_express.txt |sed '1,3aNewline '

1 "Open Source" is a good mechanism to develop programs.

New Line

2 Apple is my favorite food.

New Line

3 Football game isn't use feet only.

New Line

4 This dress doesn ' t fit me.

5 However, this dress was about $3183 dollars.

6 GNU is free air isn't free beer.

7 She hair is very beauty.

8 I can ' t finish the test.

The range is set on line 1th to 3rd, with one row below each line new lines

C substitution, if there is a specified range, replaces the entire range with the specified content, or, if no range is specified, replaces each row of stdin with the specified content.

[Email protected] ~]# cat-n regular_express.txt |sed ' 1,3creplace line '

Replace Line

4 This dress doesn ' t fit me.

5 However, this dress was about $3183 dollars.

6 GNU is free air isn't free beer.

7 She hair is very beauty

......

You can see that the 第1-3 line is replaced by a line

[Email protected] ~]# cat-n regular_express.txt |sed ' creplace line '

Replace Line

Replace Line

Replace Line

Replace Line

......

Each row is replaced

d Delete, delete whole line according to condition

First look at the contents of the file that is not processed

[Email protected] ~]# cat-n regular_express.txt

1 "Open Source" is a good mechanism to develop programs.

2 Apple is my favorite food.

3 Football game isn't use feet only.

4 This dress doesn ' t fit me.

5 However, this dress was about $3183 dollars.

6 GNU is free air isn't free beer.

[Email protected] ~]# cat-n regular_express.txt |sed '/3/d '

1 "Open Source" is a good mechanism to develop programs.

2 Apple is my favorite food.

4 This dress doesn ' t fit me.

6 GNU is free air isn't free beer.

There is a regular condition between/and/and only the contents of that line contain 3 of this character, then the whole row is deleted. In the original content, the third line contains the line number 3, and the 5th line contains $3183, so the two lines are deleted.

Also, if you specify only a range, the contents of the range are deleted

[Email protected] ~]# cat-n regular_express.txt |sed ' 1,4d '

5 However, this dress was about $3183 dollars.

6 GNU is free air isn't free beer.

But the seemingly range and conditions cannot be removed,

I insert, similar to a, but a is inserted one line below the original line, and I is inserted before the original line.

P printing, with the-n Quiet mode parameter, and range, can easily achieve the print file of the specified line range content

[Email protected] ~]# cat-n regular_express.txt |sed-n ' 2,5p '

2 Apple is my favorite food.

3 Football game isn't use feet only.

4 This dress doesn ' t fit me.

5 However, this dress was about $3183 dollars.

S///g replacements, such as the mating range, are replaced within the range.

[Email protected] ~]# cat-n regular_express.txt |sed ' s/good/------------/g '

1 "Open Source" is a------------mechanism to develop programs.

2 Apple is my favorite food.

3 Football game isn't use feet only.

4 This dress doesn ' t fit me.

5 However, this dress was about $3183 dollars.

6 GNU is free air isn't free beer.

7 She hair is very beauty.

8 I can ' t finish the test.

9 oh! The Soup taste------------.

Ten motorcycle is cheap than car.

Linux Learning notes: SED