How to display only different rows using diff (bash) How to display only different rows using diff (bash) unix unix

How to display only different rows using diff (bash)


a.txt:

1;john;125;31;tom;56;22;jack;10;5

b.txt:

1;john;125;31;tom;58;22;jack;10;5

Use comm:

comm -13 a.txt b.txt 1;tom;58;2

The command line options to comm are pretty straight-forward:

-1 suppress column 1 (lines unique to FILE1)

-2 suppress column 2 (lines unique to FILE2)

-3 suppress column 3 (lines that appear in both files)


Assuming you want to retain only the lines unique to file 2 you can do:

comm -13 file1 file2

Note that the comm command expects the two files to be in sorted order.


Here's a simple solution that I think is better than diff:

sort file1 file2 | uniq -u

  • sort file1 file2 concatenates the two files and sorts it
  • uniq -u prints the unique lines (that do not repeat). It requires the input to be pre-sorted.