comm

comm [OPTION]... FILE1 FILE2

Compare two sorted files line by line.

When FILE1 or FILE2 (not both) is -, read standard input.

With no options, produce three-column output. Column one contains lines unique to FILE1, column two contains lines unique to FILE2, and column three contains lines common to both files.

Options

-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)

--output-delimiter=<STR>

separate columns with STR

--zero-terminated, -z

line delimiter is NUL, not newline

--total

output a summary

Examples

Produce three tab-separated columns: lines only in first file, lines only in second file and common lines:

comm {{file1}} {{file2}}

Print only lines common to both files:

comm -12 {{file1}} {{file2}}

Print only lines common to both files, reading one file from stdin:

cat {{file1}} | comm -12 - {{file2}}

Get lines only found in first file, saving the result to a third file:

comm -23 {{file1}} {{file2}} > {{file1_only}}

Print lines only found in second file, when the files aren't sorted:

comm -13 <(sort {{file1}}) <(sort {{file2}})

The examples are provided by the tldr-pages project under the CC BY 4.0 License.

Please note that, as uutils is a work in progress, some examples might fail.