Linux comm Command

Linux Commands Encyclopedia

The Linux comm command is used to compare two sorted files.

This command compares the differences between two sorted files line by line, and displays the results. If no parameters are specified, the results will be displayed in 3 columns: column 1 contains lines that appear only in the first file, column 2 contains lines that appear only in the second file, and column 3 contains lines that appear in both the first and second files. If the given file name is-, the comm command will read data from standard input.

Syntax

comm [-123][--help][--version][第1个文件][第2个文件]

Parameters：

• -1 Do not display lines that appear only in the first file.
• -2 Do not display lines that appear only in the second file.
• -3 Do not display lines that appear in both the first and second files.
• --help Online help.
• --version Display version information.

Examples

The contents of aaa.txt and bbb.txt are as follows:

[root@localhost text]# cat aaa.txt 
aaa 
bbb 
ccc 
ddd 
eee 
111 
222
[root@localhost text]# cat bbb.txt
bbb 
ccc 
aaa 
hhh 
ttt 
jjj

The output after executing the comm command is as follows:

[root@localhost text]# comm aaa.txt bbb.txt 
aaa
                bbb
                ccc
        aaa
ddd
eee
111
222
        hhh
        ttt
        jjj
第一列  第二列  第三列

The first column of the output contains only lines that appear in aaa.txt, the second column contains lines that appear in bbb.txt, and the third column contains lines that appear in both aaa.txt and bbb.txt. The columns use tabs\tas the delimiter.

Linux Commands Encyclopedia