Simple Linux Command Line notes: comm

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• Parameters
• Option
• Note:
• Example

Compare sorted files

Comm [Options]File1 file2

 

Comm compares two sorted files row by row. The display result includes three columns:

Column 1st is a row found only in file1, Column 2nd is a row found only in file2, and column 3rd is a public row of two files.

 

Parameters

ParametersFile1AndFile2IsCommThe path name of the file to be compared. Use a hyphen(-)To replaceFile1OrFile2,CommReads the input information from the standard input.

 

Option

-1: The 1st column is not displayed (that is, only the rows found in file1 are not displayed)

-2: The 2nd column is not displayed (that is, only the rows found in file2 are not displayed)

-3: do not display the 3rd columns (that is, do not display the rows found in both files)

 

Note:

If files are not sorted, comm cannot work normally.

There is a tab in front of no row in Column 2nd and two tabs in front of each row in column 3rd

 

Example

Original file

 
$CatAbbbbbcccccdddddeeeeefffff $CatBaaaaadddddeeeeeggggghhhhh
 

 

Comm

 
$ Comm a B aaaaabbbbbccccc ddddd eeeeefffff ggggg hhhhh $
 

Compare sorted files A and B

 

Comm-12

 
$ Comm-12A B dddddeeeee
 

Show only public rows