yq/commands/compare.md

description

description
Deeply compare two yaml documents

Compare

yq compare <yaml_file_1> <yaml_file_2> <path_expression>

Compares the matching yaml nodes at path expression in the two yaml documents. See path expression for more details. Difference calculated line by line, and is printed out line by line where the first character of each line is either:

• `` a space, indicating no change at this line
• - a minus ,indicating the line is not present in the second document it's removed
• + a plus, indicating that the line is not present in the first document it's added

If there are differences then yq will print out the differences and exit with code 1. If there are no differences, then nothing will be printed and the exit code will be 0.

Example data

Given data1.yaml

"apples": are nice
somethingElse: cool # this is nice
favouriteNumbers: [1,2,3]
noDifference: it's the same

and data2.yaml

apples: are nice
somethingElse: cool # yeah i like it
favouriteNumbers:
- 1
- 3
- 4
noDifference: it's the same

Basic

Basic will compare the yaml documents 'as-is'

yq compare data1.yaml data2.yaml

yields

-"apples": are nice
-somethingElse: cool # this is nice
-favouriteNumbers: [1, 2, 3]
+apples: are nice
+somethingElse: cool # yeah i like it
+favouriteNumbers:
+- 1
+- 3
+- 4
 noDifference: it's the same

Formatted

Most of the time, it will make sense to format the documents before comparing:

yq compare --prettyPrint data1.yaml data2.yml

yields

 apples: are nice
-somethingElse: cool # this is nice
+somethingElse: cool # yeah i like it
 favouriteNumbers:
 - 1
-- 2
 - 3
+- 4
 noDifference: it's the same

Using path expressions

Use path expressions to compare subsets of yaml documents

yq compare -P data1.yaml data2.yml favouriteNumbers

yields

 - 1
-- 2
 - 3
+- 4