Method 1 : use command comm to compare two sorted files line by line.
Usage: comm [OPTION]... FILE1 FILE2
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.
-1 suppress lines unique to FILE1
-2 suppress lines unique to FILE2
-3 suppress lines that appear in both files
Example:
file1.txt content
# cat file1.txt kelvin@example.com ryan@alpha.com
file2.txt content
# cat file2.txt ryan@alpha.com susan@sina.com
Show content appears in both files
#comm -12 file1.txt file2.txt ryan@alpha.com
Method 2: use command diff to compare 2 files line by line
Usage: diff [OPTION]... FILES
Example
# diff file1.txt file2.txt 1d0 < kelvin@example.com 2a2 > susan@sina.com
Method 3: use command sdiff to compare side-by-side merge of file differences
Usage: sdiff [OPTION]... FILE1 FILE2
Example
# sdiff file1.txt file2.txt kelvin@example.com < ryan@alpha.com ryan@alpha.com > susan@sina.com
If you enjoyed this article, please consider sharing it!
