Posted On 2007-04-27 by FortyPoundHead
Keywords: Command Reference
Tags: Linux Commandline Linux
Views: 1481

Common - compare two sorted files line by line and write to standard output:
the lines that are common, plus the lines that are unique.

comm [options]... File1 File2

-1 suppress lines unique to file1
-2 suppress lines unique to file2
-3 suppress lines that appear in both files

A file name of `-'' means standard input.Before `comm'' can be used, the input files must be sorted using the collating sequence specified by the `LC_COLLATE'' locale, with trailing newlines significant. If an input file ends in a non-newline character, a newline is silently appended. The `sort'' command with no options always outputs a file that is suitable input to `comm''.

With no options, `comm'' produces 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. Columns are separated by a single TAB character.

The options `-1'', `-2'', and `-3'' suppress printing of the corresponding columns.

Unlike some other comparison utilities, `comm'' has an exit status that does not depend on the result of the comparison. Upon normal completion `comm'' produces an exit code of zero. If there is an error it exits with nonzero status.

About the Author

FortyPoundHead has posted a total of 1974 articles.


Comments On This Post

No comments on this post yet!

Do you have a thought relating to this post? You can post your comment here. If you have an unrelated question, you can use the Q&A section to ask it.

Or you can drop a note to the administrators if you're not sure where you should post.

Your IP address is:

Before you can post, you need to prove you are human. If you log in, this test goes away.

Recent Forum Posts

SSL Now Active
dwirch posted on June 16, 2017 at about 8:40 in Site News

SSL Now Active
dwirch posted on June 13, 2017 at about 7:59 in Site News

Coding Archive?
dwirch posted on June 3, 2017 at about 12:54 in Site News

Job Spammer: Bharti Jigyasi
dwirch posted on June 2, 2017 at about 16:57 in Spammers

Coding Archive?
dwirch posted on May 25, 2017 at about 12:38 in Site News

BWASL returns
dwirch posted on May 13, 2017 at about 15:24 in Site News