How to combine wildcard(s) with environment variable in search? - yq

Question

Is it possible to use an environment variable with wildcards in a query?
Given:
LevelA:
levelB:
- sometexthere
- other.value.here
The following query:
yq eval '.LevelA.levelB.[] | select(. == "*text*")' $file
returns: sometexthere.
An environment variable can also be used:
A="sometexthere" yq eval '.LevelA.levelB.[] | select(. == env(A) )' $file
to return the same value: sometexthere. However, this is a little pointless since the output is identical to the input variable value.
If wildcards are combined with the environment variable (to match a partial string), the command returns nothing:
A=text yq eval '.LevelA.levelB.[] | select(. == "*env(A)*")' $file
Is there another way possible to search with yq for a partial string using an environment variable?

Answer 1

You do not need the env() operator to achieve this. Instead, use single quote to concatenate shell variables in your query.
A="text"
yq eval '.LevelA.levelB.[] | select(. == "*'$A'*" )' file.yml
output:
sometexthere
With this technique, you can leverage bash parameter-expansions.
I have added text with space to the levelB to demonstrate.
# file.yml
LevelA:
levelB:
- sometexthere
- other.value.here
- text with space
Given the variable A="without space", use substitution ${A/out/} to remove the first occurrence of the string "out". The select operator will now search for the wildcard
string "*with space*".
A="without space"
yq eval '.LevelA.levelB.[] | select(. == "*'"${A/out/}"'*" )' file.yml
# | | || | || | |
# | | || | || | └> (a.1) end yq query
# | | || | || └> (b) end string
# | | || | |└> (a.2) open yq query (end concat)
# | | || | └> (c) bash double quote
# | | || └> remove the first occurent of "out"
# | | |└> (c) bash double quote
# | | └> (a.2) close yq query (begin concat)
# | └> (b) begin string
# └> (a.1) start yq query
output:
text with space