Linux notes () Contact and expansion of SED and awk

sed exercises

Copy/etc/passwd to/root/test.txt, print all lines with SED

[Email protected] sed]# sed-n ' 1, $p ' passwd

Print 3 to 10 lines of test.txt

[[email protected] sed]# sed-n ' 3,10 ' P passwd

Print the line containing ' root ' in test.txt

[[email protected] sed]# sed-n '/root/' P passwd

Delete Test.txt 15 rows and all subsequent rows

[[Email protected] sed]# sed ' 15,$ ' d passwd

Delete rows containing ' bash ' in Test.txt

[[Email protected] sed]# sed '/bash/' d passwd

Replace ' root ' as ' Toor ' in Test.txt

[[Email protected] sed]# sed ' s/root/toor/g ' passwd

Replace Test.txt '/sbin/nologin ' as '/bin/login '

[[Email protected] sed]# sed ' s#sbin/nologin#bin/login#g ' passwd

Delete all the numbers in rows 5 through 10 in Test.txt

[[Email protected] sed]# sed ' 5,10s/[0-9]//g ' passwd

Delete all special characters in test.txt (except for numbers and uppercase and lowercase letters)

[[Email protected] sed]# sed ' s/[^a-za-z0-9]//g ' passwd

Swap the first and last words in the test.txt position

[Email protected] sed]# sed ' s/\ (^[a-za-z][a-za-z]*\) \ ([^a-za-z].*\) \ ([^a-za-z]\] \ ([a-za-z][a-za-z]*$\)/\4\2\3\1/' passwd bash:x:0:0:root:/root:/bin/root-za-z]*$\)/\4\2\3\1/' passwd

Replace the first number and the last word that appear in the test.txt position

[[Email protected] sed]# sed ' s#\ ([^0-9][^0-9]*\) \ ([0-9][0-9]*\] \ ([^0-9].*\) \ ([^a-za-z]\] \ ([a-za-z][a-za-z]*$\) #\1 \5\3\4\2# ' passwd

Move the first number in the Test.txt to the end of a line

[[Email protected] sed]# sed ' s#\ ([^0-9][^0-9]*\) \ ([0-9][0-9]*\] \ ([^0-9].*$\) #\1\3\2# ' passwd

Test.txt 20 to the end of the line Plus ' AAA: '

[[Email protected] sed]# sed ', $s/^.*$/aaa:&/' passwd

SED expansion

1. How to intercept a specific line in a file

[email protected] sed]# cat Test.txt

Ert

Fff

**

[ABCFD]

123

324

444

[Rty]

**

Fgfgf

How to intercept [ABCFD] to [rty] this paragraph?

Answer: [[email protected] sed]# sed-n '/\[abcfd\]/,/\[rty\]/p ' test.txt

2.sed how to convert uppercase and lowercase letters

(1) Turn all lowercase into uppercase

[[Email protected] sed]# sed ' s/[a-z]/\u&/g ' test.txt

(2) Turn all uppercase letters into lowercase

[[Email protected] sed]# sed ' s/[a-z]/\l&/g ' test.txt

(3) Capitalize the first lowercase letter of each word

[[Email protected] sed]# sed ' s/\b[a-z]/\u&/g ' test.txt

3.sed the last number in a row of a file

[email protected] sed]# cat Test.txt

Ert

Fff

**

[ABCFD]

123

324

444

[Rty]

**

Fgfgf

[[Email protected] sed]# sed ' s/\ (^[0-9].*\)/\1 12/' Test.txt

4. How to use SED to print rows from 1 to 100 lines containing a string

[email protected] sed]# cat Test.txt

Ert

Fff

**

[ABCFD]

123

324

444

[Rty]

**

Fgfgf

Answer: [[email protected] sed]# sed-n ' 1,100{/fd/p} ' test.txt

Fff

[ABCFD]

Fgfgf

Multi-character Support:

[[email protected] sed]# sed-n ' 1,100{/ert/p;/1./p} ' test.txt

Ert

123

5.sed Delete the next line of a keyword to the last line

awk Exercises

Print the entire test.txt with awk (the following is done with the awk tool for Test.txt)

[[email protected] sed]# awk ' {print $} ' passwd

Find all rows that contain ' bash '

[Email protected] sed]# awk '/bash/' passwd

Use ': ' as a delimiter to find a line with a third paragraph equal to 0

[Email protected] sed]# awk-f ': ' $3==0 ' passwd

Use ': ' as a delimiter to find the first line of ' root ' and replace the ' root ' of that segment with ' Toor ' (which can be used together with SED)

[Email protected] sed]# awk-f ': ' $1==root ' |sed ' s/root/toor/g ' passwd

Use ': ' As a delimiter to print the last paragraph

[[email protected] sed]# awk-f ': ' {print $NF} ' passwd

Print all rows with a number of rows greater than 20

[Email protected] sed]# awk ' nr>20 ' passwd

Use ': ' As a delimiter to print all third paragraphs less than the fourth paragraph

[Email protected] sed]# awk-f ': ' $3<$4 ' passwd

Use ': ' As a delimiter, print the first paragraph and the last paragraph, and the middle with ' @ ' connection (for example, the first line should be the form of ' [email Protected]/bin/bash ')

[[email protected] sed]# awk-f ': ' {' Print $ ' @ ' $NF} ' passwd

Use ': ' As a delimiter to add the fourth paragraph of the entire document, summing

[Email protected] sed]# awk-f ': ' {(tot=tot+$4)}; END {print tot} ' passwd

Copy/etc/passwd to/root/test.txt, print all lines with SED

[Email protected] sed]# sed-n ' 1, $p ' passwd

Print 3 to 10 lines of test.txt

[[email protected] sed]# sed-n ' 3,10 ' P passwd

Print the line containing ' root ' in test.txt

[[email protected] sed]# sed-n '/root/' P passwd

Delete Test.txt 15 rows and all subsequent rows

[[Email protected] sed]# sed ' 15,$ ' d passwd

Delete rows containing ' bash ' in Test.txt

[[Email protected] sed]# sed '/bash/' d passwd

Replace ' root ' as ' Toor ' in Test.txt

[[Email protected] sed]# sed ' s/root/toor/g ' passwd

Replace Test.txt '/sbin/nologin ' as '/bin/login '

[[Email protected] sed]# sed ' s#sbin/nologin#bin/login#g ' passwd

Delete all the numbers in rows 5 through 10 in Test.txt

[[Email protected] sed]# sed ' 5,10s/[0-9]//g ' passwd

Delete all special characters in test.txt (except for numbers and uppercase and lowercase letters)

[[Email protected] sed]# sed ' s/[^a-za-z0-9]//g ' passwd

Swap the first and last words in the test.txt position

[Email protected] sed]# sed ' s/\ (^[a-za-z][a-za-z]*\) \ ([^a-za-z].*\) \ ([^a-za-z]\] \ ([a-za-z][a-za-z]*$\)/\4\2\3\1/' passwd bash:x:0:0:root:/root:/bin/root-za-z]*$\)/\4\2\3\1/' passwd

Replace the first number and the last word that appear in the test.txt position

[[Email protected] sed]# sed ' s#\ ([^0-9][^0-9]*\) \ ([0-9][0-9]*\] \ ([^0-9].*\) \ ([^a-za-z]\] \ ([a-za-z][a-za-z]*$\) #\1 \5\3\4\2# ' passwd

Move the first number in the Test.txt to the end of a line

[[Email protected] sed]# sed ' s#\ ([^0-9][^0-9]*\) \ ([0-9][0-9]*\] \ ([^0-9].*$\) #\1\3\2# ' passwd

Test.txt 20 to the end of the line Plus ' AAA: '

[[Email protected] sed]# sed ', $s/^.*$/aaa:&/' passwd

Print the entire test.txt with awk (the following is done with the awk tool for Test.txt)

[[email protected] sed]# awk ' {print $} ' passwd

Find all rows that contain ' bash '

[Email protected] sed]# awk '/bash/' passwd

Use ': ' as a delimiter to find a line with a third paragraph equal to 0

[Email protected] sed]# awk-f ': ' $3==0 ' passwd

Use ': ' as a delimiter to find the first line of ' root ' and replace the ' root ' of that segment with ' Toor ' (which can be used together with SED)

[Email protected] sed]# awk-f ': ' $1==root ' |sed ' s/root/toor/g ' passwd

Use ': ' As a delimiter to print the last paragraph

[[email protected] sed]# awk-f ': ' {print $NF} ' passwd

Print all rows with a number of rows greater than 20

[Email protected] sed]# awk ' nr>20 ' passwd

Use ': ' As a delimiter to print all third paragraphs less than the fourth paragraph

[Email protected] sed]# awk-f ': ' $3<$4 ' passwd

Use ': ' As a delimiter, print the first paragraph and the last paragraph, and the middle with ' @ ' connection (for example, the first line should be the form of ' [email Protected]/bin/bash ')

[[email protected] sed]# awk-f ': ' {' Print $ ' @ ' $NF} ' passwd

Use ': ' As a delimiter to add the fourth paragraph of the entire document, summing

[Email protected] sed]# awk-f ': ' {(tot=tot+$4)}; END {print tot} ' passwd

AWK expands

1. Use of the Gsub function in awk
   

awk ' Gsub (/www/, "abc") '/ETC/PASSWD//passwd file replace all www with ABC

2. Merge the same lines in the file into one line

Paste filename1 filename2

Cat A.txt
1 2 3
4 5 6
a b c

Cat B.txt
3 2 1
6 5 4
c B a

the paste a.txt b.txt result is
1 2 3 3 2 1
4 5 6 6 5 4
a b c C b a

If you want to connect at two file connections with a specified character, you can also use-D to specify
paste-d ' + ' a.txt b.txt
result is
1 2 3+3 2 1
4 5 6+6 5 4
a b c+c b a

Awk's more detailed usage : http://www.cnblogs.com/emanlee/p/3327576.html

Linux notes () Contact and extension of sed and awk