Toolbox Aid

August 12th, 2024 1:42 PM Mr. Q Categories: Command

Description:
The comm command compares two sorted files line by line and outputs three columns:

1. Lines unique to the first file
2. Lines unique to the second file
3. Lines common to both files.

Command:

comm file1.txt file2.txt

Sample Input

file1.txt:

apple
banana
cherry

file2.txt:

banana
cherry
date

Sample Output:

        banana
        cherry
apple
        date

Explanation:

• Column 1: Lines unique to file1.txt (apple).
• Column 2: Lines unique to file2.txt (date).
• Column 3: Lines common to both files (banana, cherry).

Options:

• -1: Suppress the first column.
• -2: Suppress the second column.
• -3: Suppress the third column.

Example with Options

To display only lines that are common to both files:

comm -12 file1.txt file2.txt

Sample Output with -12:

banana
cherry

This command is useful for comparing files, finding unique or common lines between files, and for various text processing tasks.