Combine common values from 2 input files into one output file?

[glimberg]

I'm trying to combine all the common values from 2 separate input files into a output file. Example below.

File1:

a: b
c: d
e: f
g: h

File2:

a: b
g: h
i: j

Output:

a: b
g: h

Is this possible?

[mikefarah]

From what I can tell - you are choosing only the keys that are both in file 1 and file 2 - and I'm going to assume that showing the values from file 1 is sufficient (since they are the same in file2).

In that case, you can use pick to pick the keys in file 1 from the set of keys in file 2:

yq 'pick(load("file2.yaml") | keys)' file1.yaml 
a: b
g: h

[glimberg]

Don't think this does the trick. I'm trying to select the keys whose values are equivalent in both files. This will print the key & value from file1 if the key also exists in file2

[dudicoco]

@mikefarah is there a way to get the unique key and value combinations as @glimberg stated?

[mikefarah]

Ah my apologies, if you want to only get the entries in file 1 that are in file 2; you can do it like this:

yq 'load("data2.yaml") as $f2 | with_entries( select($f2[.key] == .value) )' data1.yaml

Explanation:

• load file 2 as $f2
• with_entries(...) iterate over each entry in file 1
• select($f2[.key] == .value) only select entries in file 1 if its in file 2 with the same value

[dudicoco]

@mikefarah thanks, this works only for root keys. Is there a way to compare recursively all nested key values as well?