Toolbox Aid

August 12th, 2024 12:43 PM Mr. Q Categories: Command

The join command is used to merge lines of two files based on a common field. It is commonly used for combining data from two files with a shared key or column.

Command:

join [options] file1 file2

Examples

1. Join Two Files on the First Field

   join file1.txt file2.txt

Sample File (file1.txt):

   1 Alice
   2 Bob
   3 Charlie

Sample File (file2.txt):

   1 Engineer
   2 Designer
   3 Manager

Sample Output:

   1 Alice Engineer
   2 Bob Designer
   3 Charlie Manager

2. Join on a Specific Field and Use a Custom Delimiter

   join -t ',' -1 2 -2 1 file1.csv file2.csv

Sample File (file1.csv):

   Name,1
   Bob,2
   Charlie,3

Sample File (file2.csv):

   1,Engineer
   2,Designer
   3,Manager

Sample Output:

   Bob,2,Designer
   Charlie,3,Manager

3. Print Unmatched Lines from Each File

   join -v 1 file1.txt file2.txt

Sample File (file1.txt):

   1 Alice
   2 Bob
   4 Dave

Sample File (file2.txt):

   1 Engineer
   2 Designer
   3 Manager

Sample Output:

   4 Dave

4. Join Files Using a Different Field

   join -1 2 -2 1 file1.txt file2.txt

Sample File (file1.txt):

   Alice 1
   Bob 2
   Charlie 3

Sample File (file2.txt):

   Engineer 1
   Designer 2
   Manager 3

Sample Output:

   Alice 1 Engineer
   Bob 2 Designer
   Charlie 3 Manager

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The join command is effective for combining data based on a shared key or column, making it useful for various data processing tasks.