Awk array statistics, awk Array

Awk array statistics, awk Array

Process the following file content, retrieve the domain name andDomain Name countSorting: (Baidu and sohu interview questions)

1 http://www.etiantian.org/index.html2 http://www.etiantian.org/1.html3 http://post.etiantian.org/index.html4 http://mp3.etiantian.org/index.html5 http://www.etiantian.org/3.html6 http://post.etiantian.org/2.html

Results:

mp3.etiantian.org 1post.etiantian.org 2www.etiantian.org 3

Ideas:

1. Retrieve Domain Name

   1. Take the second column (Domain Name) with a slash as the kitchen knife)

1. Processing

   1. Create an array

   2. Use the second column (Domain Name) as the subscript of the array

   3. Calculate the quantity in a way similar to I ++

2. Output results after statistics

 

1. view the files to be processed

1 [root@martin ~]# cat test.txt 2 http://www.etiantian.org/index.html3 http://www.etiantian.org/1.html4 http://post.etiantian.org/index.html5 http://mp3.etiantian.org/index.html6 http://www.etiantian.org/3.html7 http://post.etiantian.org/2.html

2. Take the diagonal line as the delimiter and retrieve the second column. + indicates continuous.

1 [root@martin ~]# awk -F "/+" '{print $2}' test.txt 2 www.etiantian.org3 www.etiantian.org4 post.etiantian.org5 mp3.etiantian.org6 www.etiantian.org7 post.etiantian.org

3. Create an array and perform statistics

1 [root @ martin ~] # Awk-F "/+" '{hotel [$2]} 'test.txt # create an array 2 [root @ martin ~] # Awk-F "/+" '{hotel [$2]; print $2}' test.txt # create an array and output the element name through print 3 www. etiantian. org4 www. etiantian. org5 post. etiantian. org6 mp3.etiantian. org7 www. etiantian. org8 post.etiantian.org

1 [root @ martin ~] # Awk-F "/+" '{hotel [$2] ++} 'test.txt # Count the array with the same underlying criteria 2 [root @ martin ~] # Awk-F "/+" '{hotel [$2] ++; print $2, hotel [$2]} 'test.txt # print the output element name and statistics 3 www.etiantian.org 14 www.etiantian.org 25 post.etiantian.org 16 mp3.etiantian.org 17 www.etiantian.org 38 post.etiantian.org 2

$2 represents the second column of each row and is a variable. hotel [$2] ++ is similar to I ++, just replace variable I with array hotel [$2]

4. After the statistics are complete, print the output Array Using the for loop. Different tables and corresponding statistics

1 [root@martin ~]# awk -F "/+" '{hotel[$2]++}END{for(pole in hotel) print pole,hotel[pole]}' test.txt2 mp3.etiantian.org 13 post.etiantian.org 24 www.etiantian.org 3

1. Optimize the display and format the output. 2 [root @ martin ~] # Awk-F "/+" '{hotel [$2] ++} END {for (pole in hotel) print pole, hotel [pole]} 'test.txt | sort-k2 | column-t3 mp3.etiantian.org 14 post.etiantian.org 25 www.etiantian.org 3

5. Count the linux system's history using the first 10 commands

 1 [root@martin ~]# history|awk '{order[$2]++}END{for(n in order) print n,order[n]}'|sort -rnk2|head|column -t 2 awk                          54 3 history|awk                  44 4 [                            22 5 ll                           19 6 rpm                          12 7 yum                          8 8 w                            6 9 uname                        610 history                      611 /etc/rc.d/init.d/keepalived  5

 

This article refer to from "Li Dao's blog", the original address http://lidao.blog.51cto.com/3388056/1912219