Hack 20. Join Command Examples

by Ramesh

Join command combines lines from two files based on a common field.

In the example below, we have two files – employee.txt and salary.txt. Both have employee-id as common field. So, we can use join command to combine the data from these two files using employee-id as shown below.

$ cat employee.txt
 
100 Jason Smith
200 John Doe
300 Sanjay Gupta
400 Ashok Sharma
 
$ cat bonus.txt
 
100 $5,000
200 $500
300 $3,000
400 $1,250
 
$ join employee.txt bonus.txt
 
100 Jason Smith $5,000
200 John Doe $500
300 Sanjay Gupta $3,000
400 Ashok Sharma $1,250