Editing Linux 101 hacks (section)

=='''Hack 23. Sort Command'''==


Sort command sorts the lines of a text file. Following are several practical examples on how to use the sort command based on the following sample text file that has employee information in the format:


employee_name:employee_id:department_name.


$ '''cat names.txt'''


Emma Thomas:100:Marketing


Alex Jason:200:Sales


Madison Randy:300:Product Development


Sanjay Gupta:400:Support


Nisha Singh:500:Sales

'''Sort a text file in ascending order'''


$ '''sort names.txt'''


Alex Jason:200:Sales


Emma Thomas:100:Marketing


Madison Randy:300:Product Development


Nisha Singh:500:Sales


Sanjay Gupta:400:Support


'''Sort a text file in descending order'''


$ '''sort -r names.txt'''


Sanjay Gupta:400:Support


Nisha Singh:500:Sales


Madison Randy:300:Product Development


Emma Thomas:100:Marketing


Alex Jason:200:Sales


'''Sort a colon delimited text file on 2<sup>nd</sup> field (employee_id)'''


$ '''sort -t: -k 2 names.txt'''


Emma Thomas:100:Marketing


Alex Jason:200:Sales


Madison Randy:300:Product Development


Sanjay Gupta:400:Support


Nisha Singh:500:Sales


'''Sort a tab delimited text file on 3rd field (department_name) and suppress duplicates'''


$ '''sort -t: -u -k 3 names.txt'''


Emma Thomas:100:Marketing


Madison Randy:300:Product Development


Alex Jason:200:Sales


Sanjay Gupta:400:Support


'''Sort the passwd file by the 3<sup>rd</sup> field (numeric userid)'''


$ '''sort -t: -k 3n /etc/passwd | more'''


root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin


'''Sort /etc/hosts file by ip-addres'''


$ '''sort -t . -k 1,1n -k 2,2n -k 3,3n -k 4,4n /etc/hosts'''


127.0.0.1 localhost.localdomain localhost 192.168.100.101 dev-db.thegeekstuff.com dev-db 192.168.100.102 prod-db.thegeekstuff.com prod-db 192.168.101.20 dev-web.thegeekstuff.com dev-web 192.168.101.21 prod-web.thegeekstuff.com prod-web


'''Combine sort with other commands'''


o '''ps –ef | sort''' : Sort the output of process list


# '''ls -al | sort +4n ''': List the files in the ascending order of the file-size. i.e sorted by 5<sup>th</sup> filed and displaying smallest files first. 

# '''ls -al | sort +4nr ''': List the files in the descending order of the''' '''file-size. i.e sorted by 5<sup>th</sup> filed and displaying largest files first.