Evaluate select filter like Jq

[marcellodesales]

jq can filter with select

• With any Json, I can quickly parse/evaluate the string value...
  • I want to ditch jq in this case that I need to parse from yaml -> json

$ docker-compose config | \
      docker run --rm -i mikefarah/yq e '.' - -j | \
      docker run --rm -i imega/jq -r '..|.image? | select(.!=null)'
super/man:0.1.0-debug
super/man:0.1.0-dependencies
super/man:0.1.0

yqwith select?

• I can see the same result with null values...
• Here's a simple example that returns an extra null at the beginning
  • Is this a bug?

$ echo "a:\n  image: super/man:1\nb:\n  image: super/man:2\nc:\n  other: sisi" | \
    docker run --rm -i mikefarah/yq e '.. | .image' -
null
super/man:1
super/man:2
null

• Trying to use the filter: it returns the prefix with "!" as if it were the key

$ echo "a:\n  image: super/man:1\nb:\n  image: super/man:2\nc:\n  other: sisi" | \
    docker run --rm -i mikefarah/yq e '.. | .image | select(.!=null)' -
'!': null
super/man:1
super/man:2
'!': null

Question: How can I filter with select or any other function available?

• How to filter elements in any key???

[mikefarah]

Ah I haven't (yet) added a != operator, it's on the list. Until then, you can use the not operator:

yq e '.. | .image | select( (. == null) | not)' -

[marcellodesales]

@mikefarah Perfect!

$ echo "a:\n  image: super/man:1\nb:\n  image: super/man:2\nc:\n  other: sisi" | \
    docker run --rm -i mikefarah/yq e '.. | .image | select((.==null) | not)' -
super/man:1
super/man:2