replace yaml field with content of file

Question

I recently asked a question very similar to this one but failed to provide enough feedback for what would be a solution for this particular case. Opening this question with further information and context.

I have two files:

File1:

not_keyword: 'something'
keyword: 'condition'
another_not_keyword: 'something'

File2:

condition 1 condition 2 condition 3

I would like to find all occurrences of keyword in File1 and replace its content (condition) with the content of File2.

Desired output in this case:

not_keyword: 'something'
keyword: 'condition 1 condition 2 condition 3'
another_not_keyword: 'something"

It's my intent to have the replacement happen in place (directly on the file itself). A solution using gawk was given, but unfortunately I can't use anything other than sed or awk.

Answer 1

Awk approach:

awk '$1=="keyword:"{ getline k < "file2"; print $1, "\047" k "\047"; next }1' file1

The output:

not_keyword: 'something'
keyword: 'condition 1 condition 2 condition 3'
another_not_keyword: 'something'

---

As an alternative use sed in-place substitution:

$ sed -Ei "s/^(keyword: ).*/\1'$(cat file2)'/" file1

Answer 2

$ cat tst.awk
NR == FNR {
    new = (NR>1 ? new ORS : "") $0
    next
}
$1 == "keyword:" {
    $0 = $1 OFS "\047" new "\047"
}
{ print }

$ awk -f tst.awk file2 file1
not_keyword: 'something'
keyword: 'condition 1 condition 2 condition 3'
another_not_keyword: 'something'

Answer 3

The question asks for a solution using a YAML-unaware tool. I'm giving a solution using yq by Andrey Kislyuk (not Mike Farah's yq), which is YAML-aware:

yq -Y '.keyword = input' file newdata

The output, given the data in the question:

not_keyword: 'something'
keyword: 'condition 1 condition 2 condition 3'
another_not_keyword: 'something'

You may use -i or --in-place to make an in-place edit.