$ sort file1 > f1; sort file3 > f3
$ comm f1 f3
and milk duds!!
grains, protein and dairy
groups are fruits, vegetables,
groups are gum, puff pastry,
Kids, the seven basic food
Kids, the six basic food
pizza, pesticides, antibiotics,
Using the cmp command
The cmp command with no additional options confirms that files are different and points out the position of the first difference. In this case, that’s the 12th character in the first line.
$ cmp file1 file3 file1 file3 differ: byte 12, line 1 As with the diff command, there is no output if the files have identical content. $ cmp file1 file2
Using the diff3 command
The diff3 command is similar to the diff command, but allows you to compare three files instead of just two. In addition, the formatting of the output is quite different. The ====3 included in the output below means that the third file is different. It then shows the differences between the first two files and the third.
$ diff3 file1 file2 file3 ====3 1:1,3c 2:1,3c Kids, the seven basic food groups are gum, puff pastry, pizza, pesticides, antibiotics, 3:1,3c Kids, the six basic food groups are fruits, vegetables, grains, protein and dairy
Using the sdiff command
The sdiff command compares files side-by-side. In the first example, you can see that the content of both files is the same. In the second example, only the last line is the same in both files and the vertical bar noting the differences in the first lines is missing.
$ sdiff file1 file2 Kids, the seven basic food Kids, the seven basic food groups are gum, puff pastry, groups are gum, puff pastry, pizza, pesticides, antibiotics, pizza, pesticides, antibiotics, and milk duds!! and milk duds!! $ sdiff file1 file3 Kids, the seven basic food | Kids, the six basic food groups are gum, puff pastry, | groups are fruits, vegetables, pizza, pesticides, antibiotics, | grains, protein and dairy and milk duds!! and milk duds!!
Using the colordiff command
The colordiff command displays the differences between two files like the diff command but adds color when the content is different. The first command below has no output because the files are the same. The second displays the differences between the two files. On your computer screen, the font used for the first set of lines would be red and the second green.
$ colordiff file1 file2 $ colordiff file1 file3 1,3c1,3 < Kids, the seven basic food < groups are gum, puff pastry, < pizza, pesticides, antibiotics, --- > Kids, the six basic food > groups are fruits, vegetables, > grains, protein and dairy
Using the wdiff command
The wdiff command displays the content of the compared files (one copy) if they are identical. If they are different, it marks the differences using square brackets, minus and + signs to indicate their locations as in the second example below.
$ wdiff file1 file2
Kids, the seven basic food
groups are gum, puff pastry,
pizza, pesticides, antibiotics,
and milk duds!!
$ wdiff file1 file3
Kids, the [-seven-] {+six+} basic food
groups are [-gum, puff pastry,
pizza, pesticides, antibiotics,-] {+fruits, vegetables,
grains, protein and dairy+}
and milk duds!!
Wrap-up
Don’t take the limited commands in this post as meaning that these commands don’t have additional options. Use a command like wdiff –help to get a listing of the command’s options.
